Daewoo Doosan 430 440 Plus 450 460 Series Hydraulic & Hydrostatic Systems Skid Steer Loader Service

SB4149E00 Feb.2004

Hydraulic & Hydrostatic Systems For Skid Steer Loaders 430 Series 440 Plus 450 Series 460 Series

Important Safety Information

Most accidents involving product operation, maintenance and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills and tools to perform these functions properly.

Read and understand all safety precautions and warnings before operating or performing lubrication, maintenance and repair on this product.

Basic safety precautions are listed in the “Safety” section of the Service or Technical Manual. Additional safety precautions are listed in the “Safety” section of the owner/operation/maintenance publication.

Specific safety warnings for all these publications are provided in the description of operations where hazards exist. WARNING labels have also been put on the product to provide instructions and to identify specific hazards.

If these hazard warnings are not heeded, bodily injury or death could occur to you or other persons. Warnings in this publication and on the product labels are identified by the following symbol.

WARNING Improper operation, lubrication, maintenance or repair of this product can be dangerous and could result in injury or death.

Do not operate or perform any lubrication, maintenance or repair on this product, until you have read and understood the operation, lubrication, maintenance and repair information.

Operations that may cause product damage are identified by NOTICE labels on the product and in this publication.

DAEWOO cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are therefore not all inclusive. If a tool, procedure, work method or operating technique not specifically recommended by DAEWOO is used, you must satisfy yourself that it is safe for you and others. You should also ensure that the product will not be damaged or made unsafe by the operation, lubrication, maintenance or repair procedures you choose.

The information, specifications, and illustrations in this publication are on the basis of information available at the time it was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service given to the product. Obtain the complete and most current information before starting any job. DAEWOO dealers have the most current information available.

1

Index Systems Operation Hydraulic System....................................................... 5 HST System............................................................... 6 Hydraulic Control Valve ............................................. 8 Optional Bucket Self- Leveling System.................... 13 HST Pump ............................................................... 19 HST Motor ............................................................... 20

Specifications Hydrostatic Systems ................................................ 22 Hydraulic Systems ................................................... 23

Testing & Adjusting Hydraulic System..................................................... 34 Hydrostatic System.................................................. 35 Troubleshooting ....................................................... 26

Disassembly & Assembly HST Pump ............................................................... 37 HST Motor ............................................................... 40 Hydraulic Control Valve ........................................... 44 Boom Cylinder ......................................................... 47 Bucket Cylinder........................................................ 49

Hydraulic Schematic ............................................. 51

Hydraulic & Hydrostatic Systems

3

Index

Systems Operation Hydraulic System

5 6 4 7

8 To Oil Cooler 2

1

14

13 IGAT065I (1) HST Pump. (2) Hydraulic Pump.

Coupling.

(4) Control Valve. (5) Boom Cylinder. (6) Bucket Cylinder.

(7) Quick Coupling.

(8) Quick

(13) Suction Strainer. (14) Hydraulic Tank.

The hydraulic pump (2) is driven by a shaft through the hydrostatic (HST) pump (1). The fluid flows from the hydraulic tank to the hydraulic pump (2), then goes from the hydraulic pump to control valve (4).

The pump draws hydraulic oil from the tank and charges the hydraulic system with hydraulic power converted from engine power.

relief valve (2,392 psi for 430 Series, 2,840 psi for the other models), it will open and let the fluid by-pass the hydraulic circuit internally and go to the Oil Cooler and Filter. When the spool goes back to neutral position, there is fluid available for the other sections of the control valve (4). Two sections of the control valve can be used at the same time as long as the main relief valve is not open.

When all three spools (boom, bucket, attachment) of the control valve are in neutral position, the fluid goes through the control valve (4). If one of the spools is activated by pedal (boom, bucket) or electric locker switch (attachment), the fluid goes out respective port and to either the base end or the rod end of cylinders (5, 6), or attachment is operated. As the fluid goes into one end of the cylinders (5, 6), the fluid from the other side of cylinder flows back into the control valve.

The control valve (4) has an adjustable relief valve.

When the cylinders (5, 6) reach the end of the stroke, the fluid pressure reaches the setting pressure of Hydraulic & Hydrostatic Systems

5

Systems Operation

HST System

12

11 From Control Valve

3 9

2

10 1 3

13 14

Schematic for 440 Plus /450 Series /460 Series

IGAT066I (1) HST Pump. (2) Hydraulic Pump.

Filter. (13) Screen Filter.

(3) HST Motors.

(9) Check Valve.

(10) Drain Relief Valve.

(11) Oil Cooler. (12) Hydraulic

(14) Hydraulic Tank.

12

11 From Control Valve

3 9

2 1 3

13 14

Schematic for 430(PLUS)

IGAT066I (1) HST Pump. (2) Hydraulic Pump.

(3) HST Motors.

(9) Check Valve.

(11) Oil Cooler. (12) Hydraulic Filter. (13) Screen Filter.

(14) Hydraulic Tank.

Hydraulic & Hydrostatic Systems

6

Systems Operation

The fluid returned from actuating devices is sent to the oil cooler (11) for charging HST pump.

The fluid is called “drive pressure fluid”. Drive pressure is much higher than charge pressure causing the replenishing valves (check valves) of hydrostatic pump to close, allowing the flow of fluid to go the hydrostatic motors. There are four replenishing valves (check valves), two for each parts of hydrostatic pump (1). One is for forward travel and the other is for reverse travel.

HST pump supplies the oil to the left and right HST motors. HST pump drives the motor forward or reverse direction according to the control lever. The oil from the control valve flows to the HST pump through the oil cooler (11) and hydraulic filter (12).

Various hydraulic lines carry hydraulic oil among the control valve, drain relief valve (10), oil cooler (11), and filter (12).

When the loader is driven with bucket into a pile of material, there is resistance causing high pressure in drive loop.

There is relief valve built into the high relief valve/replenishing valve (for forward travel). This relief valve opens at the relief setting pressure (Refer to Specifications), the extra fluid goes from the drive loop to the charge loop to be used again.

The fluid flows from the oil cooler (11) through the filter to the center section of the hydrostatic pump (1).

The fluid is called “charge supply fluid”. In the center section of hydrostatic pump, the fluid works against two high relief/ replenishing (check) valves, flushing valve (3-position) of motors (3) and charging relief valve. The replenishing valve of hydrostatic pump and the flushing valve of motor are opened and let fluid go into the hydrostatic pump for replenishing, lubrication and cooling. The hydrostatic pump does not need the full volume of the fluid flow, so there is extra fluid. The extra fluid goes to the charge relief valve .

The hydrostatic motors (3) are “gerotor type”. In each hydrostatic motor, there are two kinds of fluid ; case drain fluid which is generated in the housing of each hydrostatic motor and, flushing fluid which is controlled by the orifice and the replenishing valve (3position) of each hydrostatic motor. These fluids go through screen filter (13) and back to the tank.

The filter (12) has a built-in by-pass valve (50 psi check valve and 40 psi pressure switch) to allow fluid flow when the fluid does not go through the filter element (plugged).

There are two parts of hydrostatic pump (1) and two hydrostatic motors (3). One part of hydrostatic pump and one of the hydrostatic motors work together as a pair to drive one side of the loader. The other part of pump and the other motor work as a pair to drive the opposite side of the loader.

The oil cooler (11) and check valve (9) are installed parallel in the charge line. Check valve (9) will be opened to protect the oil cooler (11) when the fluid is cold or the boom is lowered quickly .

Also, the drain relief valve (10) will be opened when the hydraulic pressure of charge line is higher than the cracking pressure (43 psi) to protect the oil cooler (11) and the hydraulic filter (12).

When the driving levers are in neutral, hydrostatic pump (1) and the hydrostatic motors (3) are not working, but have charge pressure. When the driving levers are moved, the swashplates in the hydrostatic pump are angled and the fluid is forced out of the pressure side of hydrostatic pump and goes to hydrostatic motors.

Hydraulic & Hydrostatic Systems

7

Systems Operation

Hydraulic Control Valve Configuration

7 LINEport K TAN "T"

6 5 4

8

s

port " "A

s port " "B

3

1 E SUR ort S E PR "P" p

2

Monoblock Valve Body

IGAT067I Configuration of Hydraulic Control Valve (1) Spool.

(2) Dust Cover Plate.

(6) Check Valves.

(3) Main Relief Valve.

(4) Float Detent Spool Control.

(7) Internal Pilot Electro-Hydraulic Spool Control.

(5) Spring Centering Spool Control.

(8) Back-Pressure Valve.

NOTE : Item (7) is only for 440 Plus, 450 Series and 460 Series.

Hydraulic & Hydrostatic Systems

8

Systems Operation

Schematic

430 Series IGAT068I

440 Plus, 450 Series and 460 Series IGAT068I

Legend P= Inlet line P1 A1-B1 A2-B2 A3-B3 T BPV CV1,CV2,CV3

MV S1,S2,S3 SC1 SC3

= Main relief valve = Spools = Float detent spool control kit = Internal pilot electro-hydraulic spool control kit SLP1,SLP2,SLP3 = Spool dust cover kit

= 2nd inlet line (plugged) = 1st section ports = 2nd section ports = 3rd section ports = Outlet line = Back-pressure valve = Load check valves

Hydraulic & Hydrostatic Systems

9

Systems Operation

Operations Spool push-in

Neutral

Load Check Valve Pressure Line

B

A

Working Ports

A

A

B 10

Spool Tank Passage Free Line

3 1

0

2 To Next Section or to Tank

A B

3 1

2

A B

To Next Section or to Tank

P

0

T P

T

IGAT069I IGAT070I

Oil discharged from the pump returns to oil cooler and HST pump through the free passage. A and B ports are blocked.

Hydraulic & Hydrostatic Systems

When the free line passage is closed, the oil discharged from the pump flows to port B. The return oil from port A is returned to the other section (series) or go through the free passage. The spool is returned to neutral by the return spring when released.

10

Systems Operation

Spool pull-out

Spool pull-out in float position

A

B

A

B

02

3 1

0

0 3

3

2

A B

P

A B

T

P

T

IGAT071I

IGAT072I

When the free line passage is closed, the oil discharged from the pump flows to port A. The return oil from port B is returned to the other section (series) or goes through the free passage.

The spool is retuned to neutral by the return spring when released.

Oil discharged from the pump returns to the valve block through the tank line. A and B are connected.

Hydraulic & Hydrostatic Systems

11

Systems Operation

Electrical Connections

A1

A2

A3

IN OUT ON OFF ON

P

B1

B2

B3

Knob with 3 Positions Push-Button

12 VDC

Battery

440 Plus, 450 Series and 460 Series IGAT0073I Configuration of Electrical Connections.

Hydraulic & Hydrostatic Systems

12

Systems Operation

Optional Bucket SelfLeveling System

Loader control valve metering and timing are important in maintaining good boom and bucket control in both conventional and self-leveling circuits.

Cavitation of the boom cylinder is possible, in the boom lowering mode, if “inlet to workport” metering lags behind “workport to return” metering. If this is allowed to happen, the bucket will hesitate during the next raise cycle while the rod end of the boom cylinder fills with oil. This may be unacceptable at some cases.

Operation

A

The following schematics and their accompanying explanations explain the operation of the Self-Level valve. Five different operating modes are described : Self-Leveling, Bucket Cylinder Extended, Retracting Boom Cylinder, Extending Bucket Cylinder, and Retracting Bucket Cylinder.

B

C

D

IGAT074I Hydraulic Circuit of Self-Leveling

The boom and bucket section of the control valve work together to position the bucket as the boom arms of the loader are being raised. When the boom spool of the control valve is engaged to raise the boom arms, the fluid from the rod end of the boom cylinders is directed through the self-leveling valve.

The self-leveling valve has a flow divider of 2-position, which directs some of the returning fluid directly back to the boom section of control valve. The remaining fluid goes through a check poppet valve (between 2position valve and 3-position valve in self-leveling valve) and to the base end of bucket cylinder. This forces the bucket cylinder rod out and adjusts the position of bucket as the boom arms are raised. Since the fluid is trapped in the base end of bucket cylinder (bucket pedal in neutral), the pressure will increase and push the flow return spool of 3-position open and allow fluid from the rod end of the bucket cylinder to return to boom section of the control valve along with the remaining of the returning fluid from the rod end of boom cylinders. When the bucket cylinders are fully extended and boom arms are still raising, fluid goes over the relief valve and back to the boom section of control valve.

Hydraulic & Hydrostatic Systems

13

Systems Operation

Self-Leveling

Boom Cylinder Port “A” Adjustable Orifice

Pump Input

Port “B”

Control Valve

Flow Divider Spool with Fixed Orifice

Return

Boom Spool “Out” Bucket Spool “Neutral”

Unloading Spool Port “C”

Port “D”

Bucket Cylinder

IGAT0075I

With the bucket spool in “Neutral” and the boom spool pulled “Out”, flow from the control valve enters the head port of the boom cylinder. As the boom cylinder extends, flow from the rod port is directed to port “A” on the self-level valve. Flow entering port “A” is able to pass through the adjustable orifice and fixed orifice in the flow divider spool. The proportion of the flow split is determined by size of the adjustable orifice.

The remainder of the flow passes through the fixed orifice, out port “B” back to the control valve. The flow that passes through the adjustable orifice flows out port “D” and goes to the head port of the bucket cylinder. The resistance on the movement of the bucket cylinder creates the pressure high enough to open the unloading spool in the self-level valve. As the bucket cylinder extends, the flow from the rod port of the bucket cylinder enters port “C” past the open unloading spool, around the flow divider spool and out port “B” back to the control valve. The purpose of the unloading spool is to prevent the bucket cylinder from dumping during the self-level cycle.

Hydraulic & Hydrostatic Systems

14

Systems Operation

Bucket Cylinder Extended

Boom Cylinder Port “A”

Pump Input

Port “B”

Control Valve Return

Boom Spool “Out” Bucket Spool “Neutral”

Unloading Spool Port “D” Port “C” Bucket Cylinder Stroked Out

IGAT0076I

In case the bucket cylinder strokes out first during the self-level cycle, or the operator moves the bucket spool to dump the bucket, the boom cylinder will continue to raise.

The unloading spool will shift to the left and unload the flow going to the bucket cylinder head port.

The oil flow goes back to control valve, thus preventing the boom cylinder from stopping during the “Raise” function.

Hydraulic & Hydrostatic Systems

15

Systems Operation

Retracting Boom Cylinder

Boom Cylinder Port “A” Lift Check

Pump Input

Port “B”

Control Valve Return

Port “C”

Boom Spool “In” Bucket Spool “Neutral”

Port “D”

Bucket Cylinder

IGAT0077I

Moving boom spool “In” the oil flow is directed to port “B” on the self-level valve. Flow enters self-level valve, opens lift check and flows out port “A” to the rod port on the boom cylinder. Flow from head port is directed back to the control valve.

Hydraulic & Hydrostatic Systems

16

Systems Operation

Extending Bucket Cylinder

Boom Cylinder Port “A”

Pump Input

Port “B”

Control Valve

Port “C”

Bucket Spool “Out”

Return Lift Check

Unloading Spool

Boom Spool “Neutral”

Port “D”

Bucket Cylinder

IGAT0078I

With the bucket spool shifted “Out”, oil flow is directed from the control valve to the head port of the bucket cylinder. The flow also enters port “D” on the self-level valve but is blocked by the lift check. Return flow also enters port “C” on the self-level valve and is blocked by the unloading spool.

Flow from the rod port is directed back to the control valve.

Hydraulic & Hydrostatic Systems

17

Systems Operation

Retracting Bucket Cylinder

Boom Cylinder Port “A”

Boom Spool “Neutral”

Pump Input Port “B” Control Valve Return Unloading Spool Port “C”

Bucket Spool “In”

Port “D”

Bucket Cylinder

IGAT0079I

With the bucket spool shifted “In”, oil flow is directed to the rod port of the bucket cylinder. Flow also enters port “C” on the self-level valve through a tee connection but is blocked by the unloading spool. Oil returning from the head port is directed back to the control valve. Oil flow from the head port enters port “D” on the self-level valve through a tee connection but is blocked by the lift check.

Hydraulic & Hydrostatic Systems

18

Systems Operation

HST Pump

Basic Closed Circuit

General Description HST Pump and motors provide an infinitely variable speed range between zero and maximum, in both forward and reverse modes of operation.

INPUT

This variable displacement pump is a compact design, using the parallel axial piston/slipper design in conjunction with a tiltable swash plate to vary the pump’s displacement. Reversing the tilt direction of the swash plate reverses the flow of oil from the pump and thus, reverses the direction of the motor output rotation.

PUMP

MOTOR

FLOW (BI-DIRECTIONAL)

OUTPUT

CASE DRAIN LINE

TANK

A direct displacement control system is used on this HST tandem pump. The swash plate control shaft is connected directly to the swash plate. Movement of the control shaft causes a proportional swash plate movement and change in pump flow. This control is located on either side of the unit.

IGAT080I

The main ports of the pump are connected by hydraulic lines to the main ports of the motors. Fluid flows, in either direction, from the pump to the motor then back to the pump in this closed circuit. Either of the hydraulic lines can be under high pressure. The direction and speed of fluid flow (and the motor output shaft rotation) depends on the position of the pump swash plate. The system pressure is determined by the machine load.

A charge relief valve and charge check valves are included in the pump end cap to control the makeup and cooling oil flow for the system. The charge check valves also incorporate the bypass valve function and high pressure relief valve function into their design.

Case Drain The pump and motor require case drain lines to remove hot fluid from the system. The pump case should be drained from its drain port to insure the case remains full of fluid. The motor housing drain port is connected to the tank.

Charge System and Filter The charge pump supplies cool fluid to the system and keeps the closed loop charged to prevent cavitation. The charge pump draws its fluid from the tank. A filter is required to insure that only clean fluid enters the system.

Hydraulic & Hydrostatic Systems

19

Systems Operation

HST Motor

Since either of the main hydraulic lines can be high pressure, four charge check valves are used to direct the charge supply into the low pressure line. These check valves (located in the pump end cap) also incorporate the high pressure relief valve function.

Any charge flow not being used for the closed circuit is discharged over a direct operating charge relief valve, through the pump and motor housings, and back to the tank.

The outer ring of the gear wheel set of HST motor is stationary part of the motor housing. This ring has internal teeth which mesh with teeth on a gear wheel or rotor which rolls inside the ring.

The motion of the rotor is transmitted to the output shaft through a drive. The drive consists of a movable shaft extension with crowned involute splines at either end. These splines match the corresponding tooth system of the output shaft and rotor, resulting in a toothed coupling between rotor and drive and between drive and shaft respectively. As it rotates, the rotor causes continuous opening and closing of tooth spaces. Four of these spaces are subjected to fluid pressure, and the opposed four are connected to return line.

High Pressure Relief Valves Four combination check /high pressure relief valves are provided in the pump end cap for overload protection. These cartridge type relief valves are factory set, and are not field adjustable.

Direct Displacement Control The direct displacement control (DDC) is located on either side of the pump, and provides a simple method of control. Movement of the swashplate control shaft produces a proportional swashplate movement and change in pump flow and/or motor shaft speed and direction.

The vehicle control system should be designed to return the swashplate to its neutral position.

Outer ring

Rotor

Zero Position

Bypass Valve In some applications it is desirable to bypass fluid around the pump allowing, for example, a vehicle to be moved short distance at low speed without running the engine. This is accomplished by manually operated bypass valves incorporated into the charge check/high pressure relief valves in the pump. When open (unscrewed 4 turns maximum), these valves connect both sides of the pump/motor closed circuit, allowing the motor to turn. Both valves must be opened for bypass operation and must be fully closed for normal operation. The engine should be shut down when opening or closing the bypass valves.

1/18 Shaft Rotation

1/9 Shaft Rotation IGAT074IP

Above pictures show three positions of the rotor, the corresponding rotor center movements, and the locations of pressure and return chambers respectively.

Hydraulic & Hydrostatic Systems

20

Systems Operation

As can be seen, the circular movement of the rotor center will cause the shaft to move in the opposite direction at eight times smaller angular velocity.

Above illustrations show the typical example which has one shaft revolution against 6 rotor center revolution with displacement of 42 chambers.

Hence 1/9 shaft revolution corresponds to 8/9 rotor center revolution causing the oil from 8 fluid chambers to be displaced, i.e. that one shaft revolution gives 8 revolutions of the rotor centre with displacement of 72 chambers.

A simple rotary channel plate guides the fluid so that pressure and suction chambers rotate synchronously with the rotor, thus causing continuous rotation.

When used in this way, the gear wheel set thus constitutes a hydraulic motor with a power which is approximately 8 times greater per revolution, compared with hydraulic motors of conventional design. The torque which is approximately 8 times greater is obtained at a speed which is 8 times lower without using a reductions gear.

Furthermore, the displacement of 72 fluid chambers per shaft revolution offers the special advantage of steady operation due to the “smoothing” effect of the increased number of chambers.

Outer ring

IGAT0823P

Above illustrations show the shaft rotation according to flow directions of two main ports of HST motor.

Disc Valve Channel Plate

Zero Position Rotor

Revolution of Rotor Center 1/4 Shaft Rotation

1/7 Shaft Rotation High Pressure

Low Pressure

IGAT0821

Hydraulic & Hydrostatic Systems

21

Systems Operation

Specifications Hydrostatic Systems Hydrostatic Transmission Pump

Charging Pump

Hydrostatic Pump

IGAT0084I

Item

Unit

Type Maximum Displacement Relief Setting Pressure Internal Charge Pump Rotation Swash Plate Operating Angle Mounting

in3 (cc)/rev psi (bar) Deg -

Shaft

Hydraulic & Hydrostatic Systems

430 Series 2.14 (35) 3,336 (230)

-

22

Specification 440 Plus 450 Series Piston, Variable Displacement 2.65 (43.5) 3,555 (250) None Clockwise ± 16 SAE 2 Bolt B Mount ANSI B92.1-1970 Class No.5 30 x 15 x 16/32

460 Series

Systems Operation

Hydraulic Motor Item

Unit

Type Displacement Mounting Shaft

430 Series

3 in (cc)/rev -

25.07 (410.8)

Specification 440 Plus 450 Series Orbit, Fixed Displacement 32.04 (523.6) SAE 4 Bolt B Mount Spline Shaft

460 Series

Hydraulic Systems Hydraulic Pump Item

Unit

430 Series

Type Capacity in3 (cc)/rev 0.98 (16.0) Maximum Pressure psi (bar) Maximum Speed rpm 3,250 Mounting Shaft Rotation * European Truck (CE Area) : 1.77 (29.0) in3(cc) / rev

Specification 440 Plus 450 Series Gear 1.47 (23.0) 1.92 (31.5) 3,335 (230) 3,000 SAE 2 Bolt A Mount SAE Spline Shaft Clockwise

460 Series *

Control Valve Item Number of spool Relief Setting Pressure (set by valve supplier)

Unit

Specification 440 Plus 450 Series 3

430 Series

ea psi

2,392 (+70) (165 (+5))

(bar)

2,840 (+70) (195 (+5))

- Series on Lift Float Function with Detent - Series on Tilt - Series on Auxiliary with (Electric) Detent

-

Circuit

460 Series

Pressure and Flow of Standard Skid Steer Loader Item Flow (maximum)

Unit LPM (GPM)

430 Series 44.8 (11.8)

psi (bar)

2,540 ± 35 (175 ± 2.4)

Maximum System Pressure at Charging pump

Hydraulic & Hydrostatic Systems

23

Specification 440 Plus 450 Series 59.8 (15.8) 82.0 (21.7)

460 Series

3,000 ± 35 (207 ± 2.4)

Systems Operation

Pressure and Flow of High Flow Skid Steer Loader Item Flow (maximum)

Unit LPM (GPM)

430 Series 98 (25.9)

psi (bar)

2,540 ± 35 (175 ± 2.4)

Maximum System Pressure at Charging pump

Specification 440 Plus 450 Series 104 (27.5) 122.3 (32.3)

460 Series

3,000 ± 35 (207 ± 2.4)

Boom Cylinder Specification Item

Unit

Type Number Cylinder Bore Cylinder Rod Stroke Mounting Plating on Rod

ea in (mm) in (mm) in (mm) -

450 460 Series Series Single Rod, Double Acting 2 1.97 (50) 2.17 (55) 2.36 (60) 1.38 (35) 1.50 (38) 1.57 (40) 31.0 (788) 39.2 (996.0) 33.5 (850) 42.0 (1065.6) Single Crest Crevice Hard chrome with 15-50 Micron Thickness

430 Series

440 Plus

Bucket Cylinder

Item Type Number Cylinder Bore Cylinder Rod Stroke Mounting Plating on Rod

Unit ea in (mm) in (mm) in (mm) -

Specification 440 Plus 450 Series 460 Series Single Rod, Double Acting 2 2.78 (63) 1.10 (30) 1.5 (38.0) 14.29 (363) 13.99 (355) 20.0 (507) Single Crest Crevice Hard chrome with 15-50 Micron Thickness 430 Series

Hydraulic Filter Item Type Filter Rating Rated Flow By-Pass Valve

Unit LPM (GPM) -

Hydraulic & Hydrostatic Systems

Specification 440 Plus 450 Series Full Flow Spin-On 13 Micron Rating of 20

430 Series

460 Series

132.5 (35) Closing PR50 PSID (Normally Open Type)

24

Systems Operation

Hydraulic Lines and Fittings Item

Unit

Type Thread Medium Pressure Line Hydraulic High Pressure Line

-

HST High Pressure Line

-

Specification 430 Series 440 Plus 450 Series 460 Series O-ring Face Seal Fitting (SAE J1453) Unified Thread is Standard SAE 100R1 Hose (SAE J517) SAE 100R2 Hose (SAE J517) SAE 100R2 Hose SAE 100R12 Hose (Parker 381-10) (SAE J517)

Fluid Capacity Item

Unit

Fuel Tank (Maximum) Hydraulic Maximum Oil Tank Hydraulic System Capacity Chain Case Oil Cooling Fluid Engine Lubrication - with filter Engine Lubrication - without filter

gal (liter) gal (liter) gal (liter) gal (liter) gal (liter) gal (liter) gal (liter)

430 Series 13.8 (52.4) 6.1 (23) 7.8 (29.5) 5.3 (20) 2.3 (8.8) 1.7 (6.5) 1.6 (6.1)

Specification 440 Plus 450 Series 14.3 (54) 18.5 (70) 8.0 (30) 13.2 (50) 11.1 (42) 12.7 (48) 5.9 (22.5) 3.7 (14) 1.2 (4.5) 2.1 (8.0) 2.0 (7.5)

460 Series 18.2 (60)

Oil Type Item Chain Case Oil Engine Oil Hydraulic Oil

Unit -

Hydraulic & Hydrostatic Systems

Specification 430 Series 440 Plus 450 Series 460 Series DEXRON 3 API CD4 Total Transmission MP (UTTO) / Mobil Fluid 423

25

Systems Operation

Testing & Adjusting

Visual Checks

Trouble shooting

A visual inspection of the hydraulic and hydrostatic system and its components is the first step when a diagnosis of a problem is made. Lower the bucket to the ground and follow these inspections;

Trouble shooting of hydraulic system would be difficult.

A list of possible problems and remedies are on the pages that follow.

1. Measure the oil level. Look for air bubbles in the oil tank.

This list of problems and remedies will only give an indication of where a problem can be and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations on the list.

Remember that a problem is not necessarily caused only by one part, but by the relation of one part with other parts. This list can not give all possible problems and remedies. The service man must find the problem and its source, then make the necessary repairs.

2. Remove the filter element and look for particles removed from the oil by the filter element. A magnet will separate ferrous particles from nonferrous particles (piston rings, O-ring seals, etc.).

3. Check all oil lines and connections for damage or leaks.

The pressure Gauge Kit and fittings can be used to make the pressure tests of the hydraulic system.

Before any test is made, visually inspect the complete hydraulic system for leakage of oil and for parts that have damage.

WARNING To prevent personal injury when testing and adjusting the hydraulic system, move the machine to a smooth horizontal location. Move away from machines and personnel that are at work. There must be only one operator. Keep all other personnel away from the machine or where the operator can see the other personnel.

Hydraulic & Hydrostatic Systems

26

Testing & Adjusting

Hydraulic System Symptom

Possible Cause Hydraulic oil level is low or empty.

Pedals are disconnected.

Contaminated/Damaged relief valve.

Damaged hydraulic pump.

Hydraulic oil is too thick.

No hydraulic cylinder action.

Hydraulic oil level is low.

Rough hydraulic cylinder action.

Pedal is hitting floor, or there is dirt under pedal.

Internal cylinder leakage.

Slow hydraulic cylinder action.

Damaged hydraulic pump.

Damaged control valve.

Hydraulic oil is too thick.

Damaged cylinder rods or seals.

Hydraulic cylinders leak oil.

Remedy Check level in tank. Add oil if necessary. Check for leaks.

Check linkage. Repair as needed.

Clean/Replace the relief valve.

Check pump. Replace if needed.

Let machine warm up before operating.

Check level in tank. Add oil if necessary. Check for leaks.

Check adjustment. Remove dirt.

Check condition of cylinders and repair as needed.

Check pump. Replace if needed.

Check valve. Replace if needed.

Let machine warm up before operating.

Repair cylinders.

Boom and Bucket Cylinders Symptom There is leakage of oil inside the cylinder or loss of boom or bucket power.

Foreign material behind the wiper rings which causes scratches on the cylinder rod.

Too much drift.

Possible Cause The piston seals are worn and let oil go through.

Cylinder has damage.

The wiper rings show wear and do not remove dirt and foreign material.

Remedy Check level in tank. Add oil if necessary. Check for leaks.

Replace cylinder assembly Replace wiper rings

Defective boom cylinder seals.

Defective control valve.

Inspect and replace seals.

Replace spool. Or replace control valve assembly (with changing oil).

Hydraulic & Hydrostatic Systems

27

Testing & Adjusting

Control Valve Symptom The boom or bucket cylinders do not hold their position with the valve control spools in neutral position.

The control valve spools do not move freely.

Control valve spools have leakage around the seals.

The bucket lowers when the boom spool is moved from neutral position to the boom-up position.

Spools do not return to neutral.

Possible Cause The valve neutral spring is week or broken.

Valve spool worn out.

Load check valve in the control valve is defective.

Dirt or foreign particles between check poppet and its seat.

The oil is too thick at low temperature.

There is foreign material in the hydraulic oil.

Bent spool.

Damage to return springs of the spools.

There is foreign material under seal.

The valve spools worn.

The seal plates are loose.

The seals have damage or are badly worn.

There is foreign material in the check valve area.

The load check valve poppet and seat show wear.

Damage to the relief valve which causes low oil pressure.

The spring broken.

The spool is bent.

The system or valve has foreign particles in it.

The fastening bolts of valve have too much torque.

The relief valve is not correctly set, or will not move in base and is worn.

There is air in the system.

Dirt or foreign particles between relief valve control poppet and its seat.

Valve body has a crack inside.

Spool not moved to a full stroke.

No electric power.

On/off pressure reducing valve blocked.

Auxiliary function doesn’t move.

High spool friction.

Too much back pressure in tank line.

Remedy Replace the neutral return spring.

Replace spool.

Replace load check valve.

Clean or replace load check valve.

Warm the oil by running of engine.

Replace the hydraulic oil and control valve.

Replace spool.

Replace return springs.

Clean.

Replace spool.

Tighten seal plates.

Replace seals.

Clean.

Replace load check valve.

Replace relief valve.

Replace spring.

Replace spool.

Clean and change oil.

Tighten with specified torque.

The relief valve is correctly set.

Or replace the relief valve.

Remove the air.

Clean.

Replace relief valve.

Inspect spool and spring. Change them if needed.

Check electric circuit.

Remove the rod pressure regulator, clean it carefully and reassemble. Or replace it.

Remove the spool, clean it carefully and reassemble.

Check hydraulic circuit and reduce back pressure lower than 20bar.

No enough back pressure on free line.

Hydraulic & Hydrostatic Systems

28

Remove the back pressure valve, clean it and reassemble.

Testing & Adjusting

Hydrostatic Pump Symptom : Difficult or Impossible to find neutral position of HST pump.

Possible cause and remedy

Check Control Input (Linkage, Pressure, Current)

OK

Check System Pressure Differential

More Then 50 psi

Defective

Repair or Replace

Adjust Swash plate to Neutral

OK

Replace Pump

Hydraulic & Hydrostatic Systems

29

Testing & Adjusting

Symptom : System Temperature is High Possible cause and remedy

Check Oil Level in Tank

OK

Inspect Heat Exchanger

Low

Check Charge Pressure (No Load and Under Load)

OK

OK

Check System Relief Pressure

Defective High

Fill to proper Level

Repair or Replace

Low

OK Inspect Charge Pump

OK

Inspect Charge Relief Valve

OK

Replace Relief Valve

Inspect Inlet of Filter Defective

Defective

Repair or Replace

Inspect Drain Relief valve

Defective

Clogged

Repair or Replace

Replace

NOTE : Drain Relief Valve is only for 440 Plus, 450 Series and 460 Series.

Symptom : Transmission Operates in one Direction Only Possible cause and remedy

Check Control Linkage

OK

Defective

Repair or Replace

Hydraulic & Hydrostatic Systems

Inspect System Check/ Relief Valves or Charge Check Valves Defective

Repair or Replace

30

Testing & Adjusting

Symptom : System Response is Sluggish Possible cause and remedy

Inspect Control Valve

Check Charge OK Pressure

Defective

Low in Neutral or Forward or Reverse

Repair or Replace

OK

Inspect Pump ByPass Valve

OK

Defective

Inspect Orifice of Control Valve

Defective

Repair or Replace

Repair or Replace

Inspect Drain Relief Valve

Repair or Replace

OK

Inspect Charge Relief Valve at Pump

OK

Inspect Inlet of Filter

OK

Inspect Charge Pump

Defective

Defective

Defective

Repair or Replace

Replace

Repair or Replace

NOTE : Drain Relief Valve is only for 440 Plus, 450 Series and 460 Series.

Hydraulic & Hydrostatic Systems

31

Testing & Adjusting

Symptom : Loss of power or transmission will not operate in either direction Possible cause and remedy

Check Oil Level in Reservoir

OK

OK

Inspect Heat Exchanger

Low

Check Charge Pressure (No Load and Under Load)

OK

Check System Pressure

High or Low

Defective Low

Fill to proper Level

Replace Relief Valve

Repair or Replace

Inspect Drain Relief Valve OK

Inspect Charge Pump

OK

OK

Inspect Charge Relief Valve

Inspect Inlet of Filter Defective Clogged

Defective

Defective Repair or Replace

Repair or Replace

Repair or Replace

Replace

NOTE : Drain Relief Valve is only for 440 Plus, 450 Series and 460 Series.

Hydraulic & Hydrostatic Systems

32

Testing & Adjusting

Hydrostatic Motor Symptom

Motor shaft does not rotate.

Possible Cause Pump does not run or runs in the wrong direction.

Motor spool has seized in housing.

Cardan shaft or spool broken (shaft and communicate valve in two).

Sand, steel chips or similar impurities in motor.

Motor shaft rotates in wrong direction.

Leakage at motor shaft.

Leak between motor spigot and housing.

Leaks between housing, spacer plate , gear wheel set and end cover, respectively.

Hydraulic & Hydrostatic Systems

The seals which are incorporated into balance plate are damaged Oil lines are wrongly connected to motor ports.

Gear-wheel and rotary valve incorrectly fitted.

Shaft seal worn out or cut.

Spigot is loose.

O-ring defective.

Screws are loose.

O-ring defective.

Steel washer defective.

33

Remedy Start pump in the correct direction of rotation.

Replace complete shaft and housing.

Replace cardan shaft or complete shaft and housing. Eliminate external force which caused the fracture.

Clean the motor and flush system thoroughly. Renew defective parts.

Change the filter.

Inspect and replace them.

Change the connections.

Adjust setting.

Replace shaft seal.

Tighten screws with specified torque. Replace O-ring.

Tighten screws with specified torque.

Replace O-ring.

Replace Steel washer

Testing & Adjusting

Hydraulic System

Model 430 Series 440 Plus 450 Series 460 Series

WARNING Hydraulic oil under pressure can remain in the system after the engine has been stopped.

Personal injury can be caused if this pressure is not released from the system before any work is started.

To be sure that the system is not pressurized, lower the boom to the ground with the engine off move the control pedals back and forth several times. This will release any pressure left in the system after shutting off the engine. The procedure must be done before any fitting, hose, or component is loosened.

Perform adjustments on level ground away traffic.

When making adjustments or taking measurements with the engine running, make sure that all personals clear of the machine.

psi 2,392 (+70) 2,840 (+70) 2,840 (+70)

bar 165 (+5) 195 (+5) 195 (+5)

7. If the relief pressure does not fall into the above range, do the steps that follow. a. With the engine off, locate the adjustment screw on the control valve. b. Loosen the lock nut and turn the adjustment screw approximately 1/8 turn. The adjustment screw is very sensitive, do not rotate it over 1/4 turn at a time. To increase the relief pressure, tighten the adjustment screw clockwise. To decrease the relief pressure, loosen it. c. Retighten the lock nut and, check out the relief pressure with above procedure. If the relief pressure still does not fall in the specific range, shut off the engine and adjust again. Repeat until the relief pressure falls into the specific range.

Check & Adjusting Procedure of Relief Pressure of Control Valve 1. If attachment is installed on the truck, take it out from truck.

2. Check the engine speed. It should be within the following range.

Model 430 Series 440 Plus 450 Series, 460 Series

Adjustment Screw

Lock nut

rpm 2,950 ± 50 2,780 ± 50 2,800 ± 50

3. Warm the hydraulic oil to the temperature 100120°F (50 ± 5°C).

A1

A2

A3

B1

B2

B3

IN

4. With the engine off, install 5000 psi (350 bar) rated pressure gage into the female coupler of the auxiliary hydraulic line(down side) on the boom.

5. Start the engine and at high idle, push the auxiliary. With keeping depressing the left side of thumb button on right driving control lever after pushing “On” switch of attachment on control panel, read the pressure gage.

IGAT0825I

6. The pressure gage should read the following range.

Hydraulic & Hydrostatic Systems

34

Testing & Adjusting

Hydrostatic System

WARNING

Start-Up Procedure of Hydrostatic System

Do not start prime mover unless pump is neutral position (0 swash plate angle). Take precautions to prevent machine movement in case pump is actuated during initial start up.

The following start-up procedure should always be followed when starting up a new installation or when restarting an installation in which either the hydrostatic pump or hydrostatic motor had been removed from the system.

Once charge pressure has been established, increase speed to normal operation speed.

Charge pressure should be 160 psi minimum. If charge pressure is incorrect, shut down and determine the cause for improper pressure.

WARNING

With motor output shaft disconnected or drive wheels raised off the ground, run system as full input and output speeds in both directions. Operate system for at least 15 minutes.

The following procedure may require the vehicle to be disabled (wheels raised off the ground, work function disconnected, etc.) while performing the procedure in order to prevent injury to the technician and by-standers.

Shut down prime mover, remove gauge, and plug ports. Check the tank level and add fluid if necessary.

The transmission is now ready for operation.

Prior to installing the hydrostatic pump and/or motor, inspect the units for damage incurred during shipping and handling. Make sure that all system components (tank, hoses, valves, fittings, oil cooler, etc) are clean prior to filling with fluid.

Fill the tank with recommended hydraulic fluid which should be passed through 10 micron filter prior to entering tank.

The inlet line leading from tank to pump must be filled prior to start up. Check inlet line for properly tightened fittings and make sure it is free of restrictions and air leaks.

Be certain to fill the hydrostatic pump and/or motor housing with clean hydraulic fluid prior to start up. Fill the housing by pouring filtered oil into the upper case drain port.

Install a 500 psi (35 bar) pressure gauge in the charge pressure gauge port to monitor the charge pressure during start-up.

With the pump swashplate in its neutral (0 angle) position, “jog” or slowly rotate prime mover until charge pressure starts to rise. Start the prime mover and run at the lowest possible RPM until charge pressure has been established. Excess air may be bled from the high pressure lines through the high pressure gages ports.

Hydraulic & Hydrostatic Systems

35

Testing & Adjusting

Hydrostatic pump Gage Installation

A

It will be necessary to install a high pressure gauge into the system pressure port (or tee into the high pressure line) to check the setting of the system pressure relief valves.

Measuring the charging pump inlet vacuum will help locate restrictions in the inlet lines, filter etc.

Case pressure readings can help locate restrictions in the return lines, oil cooler, and return filter.

B C D

Gauge Information 10000 psi (690Bar) System Pressure gauge 9/16-18 O-ring Port “A” fitting 10000 psi (690Bar) System Pressure gauge 9/16-18 O-ring Port “B” fitting 500 psi (35Bar) gauge Charge Pressure 7/8-14 O-ring fitting 500 psi (35Bar) gauge Case Pressure 1-1/16-12 O-ring fitting

Direct Displacement Control Inspect the connection of the control linkage to the swashplate control shaft to insure that the linkage is properly attached. Neutral position of the swashplate is determined by the vehicle control linkage.

A Front

B Rear

(With

C Charge Pump)

D

When a problem occurs in one direction, interchange the charge check or check/relief valves to see if the problem changes to the other direction. If so, one valve is malfunctioning or the check/relief valve cartridge does not have the proper setting pressure.

D (Less

C Charge Pump)

B Front

Check High Pressure Relief Valves

CAUTION : The relief valves are factory set and should not be tampered with except for replacing the entire cartridge. Disassembly may change the setting and cause erratic unit operation or premature failure.

A Rear

Pump Charge Relief Valve IGAT0826I

If charge pressure is low, the charge relief valve should be inspected. Inspect for foreign material holding the poppet open, and for scoring or wear on the poppet and seat in the housing.

Gauge Connections (Top View)

Adjustment of the charge pressure is accomplished by changing the shim thickness behind the spring.

B Rear (Opposite Side)

Bypass Valve The bypass function is accomplished by manually opening the charge check/high pressure relief valves.

If the system is operating hot, check that the valves are fully seated by turning the special plugs clockwise with a 5/16” internal hex wrench. Torque the plugs to 30 to 50 ft·lb (41 to 68 N·m).

B Front

IGAT0827I

Gauge Connections (Side View)

Hydraulic & Hydrostatic Systems

36

Testing & Adjusting

Disassembly & Assembly HST Pump NOTE:

Only trained personnel should disassemble.

When making repairs on hydrostatic systems, clean the work area before disassembly and keep all parts clean. Mark the match points on housing.

5

IGAT090P 1

3. Remove four check and relief valves (5). The valve may be removed from the special plug by pulling straight out.

6 3

2

IGAT088P

1. Remove the screws (1) and hydraulic pump (2) from the HST pump (3).

16

IGAT091P 4

4. Remove the charge relief valve (6) from end cap (16).

7 1

8

9

10

11

IGAT089P

2. Remove the coupling (4) from the hydraulic pump.

IGAT092P

5. Remove plug (7), O-ring (8), shim (9), spring (10) and valve poppet (11) from the charge relief valve.

NOTE:

Hydraulic & Hydrostatic Systems

37

Protect all exposed sealing surfaces and open cavities from damage and foreign material.

It is recommended that all gaskets and Orings be replaced.

Disassembly & Assembly

17

12

IGAT093P

IGAT096P

6. Remove screws (12) from the pump.

Separate the front and rear sections of pump.

(Front pump is engine side and rear pump is hydraulic pump side).

9. Remove the valve plate (17) from the end cap (16).

19

Followings are disassembly procedure of front pump.

14 18

IGAT097P

10. Remove the cylinder block (18) from the housing (19).

13

IGAT094P

24 22

7. Remove coupling (13) and O-ring (14) from the front pump.

23

21

20

IGAT098P 15

11. Remove the slipper retainer and piston assembly (20) from the cylinder block (21). Remove the slipper retainer guide (24), pins (22) and slipper hold down retainer (23) from the cylinder block.

16

IGAT095P

8. Remove screws (15) and the end cap (16) with the valve plate from the front pump.

Hydraulic & Hydrostatic Systems

38

Disassembly & Assembly

26 19

25

31 30

IGAT099P

IGAT102P

12. Remove the retaining ring (25) from the housing (19) using plier.

16. Remove the screws (30) and the trunnion covers (31) (mark the position of cover for re-assembly).

13. Remove support washer (26) and lip seal.

27

32

28

IGAT103P IGAT100P

17. Remove both bearings (32).

14. Remove retaining ring (27) and front shaft (28) with bearing from the housing.

33

28

34

29

IGAT104P

18. Remove thrust plate (33).

IGAT101P

19. Do step 14 through 18 to disassemble rear pump.

15. Remove the retaining ring (29) and press the shaft (28) out of the bearing (34).

Hydraulic & Hydrostatic Systems

NOTE:

39

There is no lip seal in the rear pump.

Remove the retaining ring at first. Then, the shaft and bearing could be removed.

Disassembly & Assembly

HST Motor

20. Assemble HST pump in the reverse order of disassembly. Refer to following torques when installing.

CAUTION : Cleanliness is extremely important when repairing a hydraulic motor. Work in a clean area.

Before disconnecting the lines, clean the port area of the motor thoroughly. Before starting the disassembly procedures, drain the oil from inside the motor.

End cap onto the housing…………………...47~61 N·m 35~45 lb·lt) Assembly of front and rear pump…………..47~61 N·m (35~45 lb·lt) Charge relief valve………………………….54~125 N·m (40~100 lb·lt)

1

Check and reliefvalve………………………41~68 N·m (31~50 lb·lt)

IGAT105P

1. Place the motor in a vise with the output shaft down. Clamp across the mounting flange of the motor not the housing. Excessive clamping pressure will cause distortion.

2. Remove four bolts (1) from motor with socket spanner.

2

IGAT106P

3. Lift the valve housing (2) straight up.

Hydraulic & Hydrostatic Systems

40

Disassembly & Assembly

3

7

4

2

IGAT107P

IGAT110P

4. Remove O-ring (3) and channel plate (4) from the valve housing (2).

7. Remove valve drive (7).

5

8

2

9

IGAT111P IGAT108P

8. Remove gear wheel set (8) from bearing housing (9).

5. Remove disc valve (5) from the valve housing (2).

6

10

8

IGAT109P

IGAT112P

6. Remove balance plate (6) from the valve housing.

Apply some clean oil for removal, if needed.

9. Remove O-ring (10) from gear wheel set (8).

Hydraulic & Hydrostatic Systems

41

Disassembly & Assembly

11 16

9

IGAT113P

IGAT116P

10. Remove cardan shaft (11) from bearing housing (9).

14. Remove shaft and bearing assembly (16) from bearing housing.

11. Separate bearing housing from the vise.

Followings are procedures for assembly of HST motor.

16 12 9

13

IGAT114P IGAT116P

12. Remove six screws (12) and front cover (13) from bearing housing.

15. Install shaft and bearing assembly (16) to bearing housing (9).

14 14

15

15

13 13

IGAT115P IGAT115P

13. Remove shaft seal (14) and O-ring (15) from front cover (13).

Hydraulic & Hydrostatic Systems

16. Install shaft seal (14) and O-ring (15) to front cover (13).

42

Disassembly & Assembly

12 8

13

9

9

IGAT119P

IGAT111P

17. Install front cover (13) to bearing housing (9) and tighten six screws (12) with torque of 24 ± 2 N·m· (210 ± 17 lb·fn).

20. Install gear wheel set (8) to bearing housing (9).

7

8

10

8

IGAT110P IGAT112P

21. Install valve drive (7) to gear wheel set (8).

18. Install O-ring (10) to gear wheel set (8).

4 11 9

IGAT124P IGAT113P

22. Install channel plate (4) with O-ring to gear wheel set.

19. Install cardan shaft (11) to bearing housing (9).

Hydraulic & Hydrostatic Systems

43

Disassembly & Assembly

1

5 4

IGAT125P

IGAT105P

23. Install disc valve (5) to channel plate (4).

26. Tighten four bolts with the torque of 140 ± 5 N·m(100 ± 4 lb·ft).

6

Hydraulic Control Valve 1 2

2

IGAT109P 3

24. Install balance plate (6) to valve housing (2).

IGAT129P 2

1. Remove four screws (1) and electro-hydraulic kit (2) from the control valve assembly (3).

NOTE:

Item (2) is only for 440 Plus, 450 Series and 460 Series.

4

IGAT106P

25. Install valve housing (2) including balance plate to motor.

2

IGAT130P

2. Remove spool assembly (4) from the electrohydraulic kit (2).

Hydraulic & Hydrostatic Systems

44

Disassembly & Assembly

20 24

6

23

19

22 21 5

IGAT131P

IGAT134P

3. Remove boot (5) and coil (6).

7. Remove joint (19), piston (21), flange (22), O-ring (23), spool control kit (20) and end cap (24).

11

9

16 28 27

25 15

14

13

12

8

10

7 26

IGAT132P IGAT135P

4. Remove tube (7), O-ring (16), pin (8), open ring (9), ring (10), spring (11), ring (12), rod (13), bushing (14) and spring (15).

8. Remove two screws (25), cover flange (26), ring (27) and O-ring (28) from the control valve.

5. Do steps 3 and 4 to disassemble the other coil assembly.

27

28 18

25

26

IGAT136P

17

9. Remove plug (25), spring (26) and piston (27) from back-pressure valve body (28).

IGAT133P

6. Remove flange (17) and O-ring (18).

Hydraulic & Hydrostatic Systems

10. Remove back-pressure valve body from the control valve.

45

Disassembly & Assembly

31 30

29

43

IGAT137P

IGAT139P

11. Remove main relief valve (29) from the control valve.

15. Remove load check valve (43) from the control valve.

12. Remove four screws (30) and float detent spool control kit (31).

16. Assemble control valve in the reverse order of disassembly. Refer to following torques when installing.

34

38

Main relief valve...........................42 N·m (31 lb·ft).

Back-pressure valve.....................42 N·m (31 lb·ft).

Load check valve.........................24 N·m (18 lb·ft).

33 39 35 40 36 41 37 42 32

IGAT138P

13. Remove boom spool assembly (32) from control valve.

14. Remove cover (33), O-ring (34), spring (35), thrust ring (36), bushing (37), cover (38), pin (39), bushing (40), spring (41) and bushing (42).

Hydraulic & Hydrostatic Systems

46

Disassembly & Assembly

Boom Cylinder of 430 Series and 450 Series

IGAT140l

1. Place the boom cylinder in a vice and remove the rod cover (3).

6. Remove the bushing (17) from the knuckle and head cover.

2. Remove rod assembly (2) from the cylinder assembly.

7. Assemble the boom cylinder in the reverse order of disassembly.

3. Remove spring pin (16), hex nut (15), piston (10) and rod cover (3) from the rod assembly.

4. Remove O-ring (11), dust ring (14), slipper seal (12) and wear ring (13) from the piston.

5. Remove dust wiper (4), back up ring (6), U-packing (5), DU-bush (7), O-ring (8) and back up ring (9) from the rod cover.

Hydraulic & Hydrostatic Systems

47

Disassembly & Assembly

Boom Cylinder of 440 Plus & 460 Series

IGAT140l

1. Place the boom cylinder in a vice and remove the rod cover (3).

6. Remove the bushing (17) from the knuckle and head cover.

2. Remove rod assembly (2) from the cylinder assembly.

7. Assemble the boom cylinder in the reverse order of disassembly.

3. Remove socket bolt (16), hard washer (15), piston (10) and rod cover (3) from the rod assembly.

4. Remove O-ring (11), wear ring (13), slipper seal (12) and wear ring (14) from the piston.

5. Remove dust wiper (4), back up ring (6), U-packing (5), DU-bush (7), O-ring (8) and back up ring (9) from the rod cover.

Hydraulic & Hydrostatic Systems

48

Disassembly & Assembly

Bucket Cylinder of 450 Series

IGAT141l

1. Place the bucket cylinder in a vice and remove the rod cover (3).

6. Remove the bushing (19) from the knuckle and head cover.

2. Remove rod assembly (2) from the cylinder assembly.

7. Assemble the bucket cylinder in the reverse order of disassembly.

3. Remove spring pin (18), hex nut (17), piston (12) and rod cover (3) from the rod assembly.

4. Remove cushion ring (11), O-ring (13), dust ring (14), slipper seal (15) and wear ring (16) from the piston.

5. Remove dust wiper (4), back up ring (6), U-packing (5), washer (10), DU bush (7), back up ring (9) and O-ring (8) from the rod cover.

Hydraulic & Hydrostatic Systems

49

Disassembly & Assembly

Bucket Cylinder of 430 Series, 440 Plus & 460 Series

IGAT141l

1. Place the bucket cylinder in a vice and remove the rod cover (3).

6. Remove the bushing (18) from the knuckle and head cover.

2. Remove rod assembly (2) from the cylinder assembly.

7. Assemble the bucket cylinder in the reverse order of disassembly.

3. Remove socket bolt (17), hard washer (16), piston (11) and rod cover (3) from the rod assembly.

4. Remove O-ring (15), wear ring (14), slipper seal (12) and wear ring (13) from the piston.

5. Remove dust wiper (4), back up ring (7), U-packing (6), washer (10), DU bush (5), back up ring (9) and O-ring (8) from the rod cover.

Hydraulic & Hydrostatic Systems

50

Disassembly & Assembly

HYDRAULIC SCHEMATIC FOR 430 Series

D500058

HYDRAULIC SCHEMATIC FOR 440 Plus, 450 Series & 460 Series

D424772

SB4038E00 Jul. 2000

Electric Systems For Skid Steer Loaders 1550XL(DSL702) 1760XL(DSL802-D430) 2060XL(DSL902)

Important Safety Information

Most accidents involving product operation, maintenance and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills and tools to perform these functions properly.

Read and understand all safety precautions and warnings before operating or performing lubrication, maintenance and repair on this product.

Basic safety precautions are listed in the “Safety” section of the Service or Technical Manual. Additional safety precautions are listed in the “Safety” section of the owner/operation/maintenance publication.

Specific safety warnings for all these publications are provided in the description of operations where hazards exist. WARNING labels have also been put on the product to provide instructions and to identify specific hazards.

If these hazard warnings are not heeded, bodily injury or death could occur to you or other persons. Warnings in this publication and on the product labels are identified by the following symbol.

WARNING Improper operation, lubrication, maintenance or repair of this product can be dangerous and could result in injury or death.

Do not operate or perform any lubrication, maintenance or repair on this product, until you have read and understood the operation, lubrication, maintenance and repair information.

Operations that may cause product damage are identified by NOTICE labels on the product and in this publication.

DAEWOO cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are therefore not all inclusive. If a tool, procedure, work method or operating technique not specifically recommended by DAEWOO is used, you must satisfy yourself that it is safe for you and others. You should also ensure that the product will not be damaged or made unsafe by the operation, lubrication, maintenance or repair procedures you choose.

The information, specifications, and illustrations in this publication are on the basis of information available at the time it was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service given to the product. Obtain the complete and most current information before starting any job. DAEWOO dealers have the most current information available.

Electric Systems

1

E/G Starting & Stop System

Electric Systems

1. E/G Starting & Stop System (1550XL(DSL702), 1760XL(DSL802-D430), 2060XL(DSL902))

3 E/G Starting & Stop System

– 12Volts, 100AH battery with 750 Cold-Cranking Amps.

– The start motor is rated 2.5 kW.

Electric Systems

2. Preheating & Charging System (1760XL(DSL802-D430))

4 Preheating & Charging System

– The Preheat Controller controls the operation of the Glow Plugs to give better starts to a cold engine.

The controller will turn ON the Preheat Lamp for 5 seconds and also activate the Preheat Relay for 7 seconds.

According to the temperature which is sensed by Thermal Sender, the time of After Heating will be set after starting.

Electric Systems

3. Preheating & Charging System (1550XL(DSL702), 2060XL(DSL902))

5 Preheating & Charging System

– The Preheat Controller controls the operation of the Glow Plugs to give better starts to a cold engine.

The controller will turn ON the Preheat Lamp for 5 seconds and also activate the Preheat Relay for 7 seconds.

According to the temperature which is sensed by Thermal Sender, the time of After Heating will be set after starting.

4. Instrument Panel Layout (1760XL(DSL802-D430))

9

2

3

10

4

5

8

6

11

7

14

1

A

16

C

B

17

D

18

12

15

19

E

A) On switch B) OFF switch C) Green indicator light D) detent switch “ON” E) Detent switch “OFF”

1) Key Switch 2) Water temperature warning light 3) Engine oil pressure warning light 4) Charge warning light 5) HST oil temperature warning light 6) HST pressure warning light 7) Oil filter warning light 8) Warning light 9) Stop light 10) Buzzer 11) Light switch 12) Pre-heat light 13) Parking brake light 14) Fuel gage 15) Hour meter 16) Fuse-lamp 17) Fuse-instrument panel 18) Fuse-start 19) Fuse-horn

Electric Systems

13

NOTE : The left-hand instrument panel is a sealed unit. Warning lamps cannot be replaced individually.

In the right-hand unit, the pre-heat light (12) and parking brake light (13) can be replaced from the back.

NOTE : Refer to 5.4.1 MONITORING SYSTEM.

6

Instrument Panel Layout

5. Instrument Panel Layout (1550XL(DSL702), 2060XL(DSL902))

15

3

2

4

5

E

11

14

D

1

B 12

10 8

6

9

7

13

A

Instrument Panel-LH

Instrument Panel-RH

A) On switch B) OFF switch C) Green indicator light D) detent switch “ON” E) Detent switch “OFF”

1) Key Switch 2) Water temperature warning light 3) Engine oil pressure warning light 4) Charge warning light 5) HST oil temperature warning light 6) HST pressure warning light 7) Oil filter warning light 8) Warning light(Yellow) 9) Stop light(Red) 10) Sediment 11) Light switch 12) Pre-heat light 13) Parking brake light 14) Fuel gage 15) Hour meter

Electric Systems

C

NOTE : Reter to MONITORING SYSTEM

7

Instrument Panel Layout

Electric Systems

6. Monitoring System (1760XL(DSL802-D430))

8 Monitoring System

Electric Systems

7. Monitoring System (1550XL(DSL702), 2060XL(DSL902))

9 Monitoring System

Operation by operator

Button(A,C)on

Detent rocker

Thumb button

forward control

switch(D,E) on

on right control

forward control

lever

panel

Attachment

Attachment

Flow out of

operation

spool

spool motion

attachment

solenoid

of hydraulic

line port on

activation

control valve

boom(left side)

panel Momentary

Pushing button(A)

Pushing switch(E)

Neutral

“ON” relay

-

-

-

Pushing switch(E)

Keep depressing

“ON” relay

FWD solenoid

Spool-out

Down side

left hand side

“F1” relay

of button

“F2” relay REV solenoid

Spool-in

Upper side

control

Pushing switch(E)

10 Detent

Keep kepressing

“ON” relay

right hand side

“R1” relay

of button

“R2” relay

Operation of the related parts in momentary control & detent control

Pushing button(C)

Either way

Either way

-

-

-

-

Pushing button(A)

Pushing switch(D)

Neutral

“ON” relay

-

-

-

FWD solenoid

Spool-out

Down side

REV solenoid

Spool-in

Upper side

-

-

-

control

“D1” relay “D2” relay Pushing switch(D)

Pushing switch(D)

Pushing button(C)

Pushing switch(E)

NOTE : Refer to Schematic-Elec for Thumb Control.

-Keep depressing

“ON” relay

left handside

“F1” relay

of button,

“F2” relay

-After that

“D1” relay

releasing button

“D2” relay

-Keep depressing

“ON” relay

right hand side

“R1” relay

of button,

“R2” relay

-After that

“D1” relay

releasing button

“D2” relay

Either way

-

8. Operation of the related parts in momentary control & detent control (1760XL(DSL802-D430), 1550XL(DSL702), 2060XL(DSL902))

mode

Relay

- Relay, solenoid valve, spool motion of control valve and direction of pump flow to attachment quick coupler port

Electric Systems

Operation

Electric Systems

9. Thumb Control (1760XL(DSL802-D430))

11 Thumb Control

Electric Systems

10. Thumb Control (1550XL(DSL702), 2060XL(DSL902))

12 Thumb Control

11. Lights and Options • Dual front and single rear area flood lights for standard.

• Available Options • Strobe light • Horn • Back up buzzer • Heater • Cigar lighter NOTE : Refer to WIRING SCHEMATIC - ELEC.

Electric Systems

13

LIGHTS and OPTIONS

12. Item Descriptions and Functions (1550XL(DSL702), 2060XL(DSL902))

4) Charge warning Light

1) Key Switch

• The light turns on when trouble occurs in the charging system.

2) Water Temperature Warning Light

5) HST Oil temperature Warning Light

¥ The light turns on when the temperature of the engine cooling water exceeds 110ûC (230 ûF).

• The light turns on when the temperaturre of the hydraulic oil to drive HST goes up to 100˚C (212 ˚F).

3) Engine Oil Pressure Warning Light

6) HST Pressure Warning Light

• The light turns on when the engine oil pressure is below 0.5 kg/cm2(15 psi).

• The light turns on when the pressure of the HST pump oil falls below 6.0 kg/cm2 (85 psi).

Electric Systems

14

Item Descriptions and Functions

7) Oil filter warning Light

10) Buzzer

• If the oil filter becomes clogged, the light turns on.

• The light turns ON when the water exceeds 100cc in the fuel filter.

8) Warning Light

11) Light Switch

• The light turns on simultaneously with Charge HST oil temperature, HST pressure and oil filter warning lights.

• Step 1 : Two front lights turn on.

• Step 2 : Two front lights and one rear light turn on simultaneously.

9) Stop Light

12) Pre-heat Light

• The light turns on simultaneously with water temperature and engine oil pressure warning lights.

• When the key is turned to the “IGN” position, the glowplug relay turns on this light.

Electric Systems

15

Item Descriptions and Functions

13) Parking Brake Light

Buzzer

• Raising the hand lever, the parking brake is engaged and the light turns on.

• The buzzer is activated simultaneously with water temperature and engine oil pressurre warning lights.

14) Fuel Gage

• Fuel gage shows the amount of fuel in the fuel tank.

15) Hour meter

• Hour meter indicates the total hours of vehicle operating.

Electric Systems

16

Item Descriptions and Functions

13. Trouble Shooting

13.2. Trouble Shooting Guide

13.1. Test Equipment

NOTE 1 : The DSL has no electrical shutdowns, only visual and auditory indicators.

The following items should be sufficient to allow you to perform most electrical troubleshooting operations on the electrical system.

NOTE 2 : The lighting, instrument panel, and start (key switch) fuses (and horn fuse-optional, if equipped) located in the right-side instrument panel are all 15-amp tube-type fuses.

• Volt/ohmmeter (Multimeter) • Jumper wires (variety of lengths) with alligator clip ends • Needle tips • External 12-volt source • Wiring diagrams

Symptom Discharged battery

Engine does not crank

The following troubleshooting guide presents possible causes and actions in a logial order from simplest/most likely to more complex/less likely (more drastic). For any symptom, if a given action does not identify the problem, proceed to the next action.

Possible Cause Loose/damaged alternator belt.

Action Tighten/replace belt.

Loose/dirty connections.

Adjust/clean clamps, posts.

Battery faulty.

Replace battery.

Alternator faulty.

Check or replace.

Battery may be discharged.

Check battery condition.

Start fuse may be blown.

Check fuse in instrument panel.

Problem in neutrl safety

Wiggle drive levers while trying to

mechanisms.

start. If engine starts, adjust neutral switches and/or centering control(s).

Neutral switch(es) may be faulty.

Jumper neutral switch(es) one at a time. If engine starts, replace neutral switch(es).

Start relay may be faulty.

Jumper start relay. If engine starts, replace start relay.

Engine cranks but does not start

Glow plug does not work

Loader is out of fuel.

Check fuel tank.

Engine has starting problem not

Check engine. See section

related to electrical system.

Engine in this manual.

Alternator may be faulty.

Check alternator.

Wiring problem.

Check glow plug wiring.

Glow plug relay may be faulty.

Check wiring to relay. Jumper relay.

If glowplug works, replace relay.

Instrument panel indicator lights do

Glow plug elements(s) may be

Check elements. If problems found,

faulty.

replace glow plug.

Fuse may be blown

Check/replace fuse in instrument panel.

not come on or give faulty indications.

Individual panel lights do not

Control unit may be faulty

Replace control unit.

Bulbs may be faulty.

Check/replace bulbs.

come on.

Wiring to light may be faulty.

Check individual wiring.

Repair faulty connections or replace wires.

Electric Systems

17

Trouble shooting

Symptom Fuel gage does not work or gigves

Possible Cause Sender wiring may be faulty.

Action Check wiring between meter and

faulty indication (other instrument

instrument panel. Check sender

panel functions are OK)

ground.

Gage may be faulty.

Replace gage.

Meter wiring may be faulty.

Check meter wiring.

are OK).

Rear or front flood lights do not

Meter may be faulty.

Replace meter.

Fuse may be blown in instrument

Check/replace fuse in instrument

turn on.

panel.

panel.

Bulb(s) may be burned out.

Check/replace bulbs.

Wiring may be faulty.

Check connections and wires.

Hour meter does not register hours (other instrument panel functions

Check connections in cab wiring connector.

Electric Systems

18

Trouble shooting

1

WIRING SCHEMATIC-ELECTRIC MODEL : 1760XL(DSL802) (FOR D430 E/G)

2

WIRING SCHEMATIC-ELEC MODEL : 1550XL(DSL702), 2060XL(DSL902)

SB4103E00 Sep. 2003

Electric Systems For Skid Steer Loaders 440Plus

Important Safety Information

Most accidents involving product operation, maintenance and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills and tools to perform these functions properly.

Read and understand all safety precautions and warnings before operating or performing lubrication, maintenance and repair on this product.

Basic safety precautions are listed in the “Safety” section of the Service or Technical Manual. Additional safety precautions are listed in the “Safety” section of the owner/operation/maintenance publication.

Specific safety warnings for all these publications are provided in the description of operations where hazards exist. WARNING labels have also been put on the product to provide instructions and to identify specific hazards.

If these hazard warnings are not heeded, bodily injury or death could occur to you or other persons. Warnings in this publication and on the product labels are identified by the following symbol.

WARNING Improper operation, lubrication, maintenance or repair of this product can be dangerous and could result in injury or death.

Do not operate or perform any lubrication, maintenance or repair on this product, until you have read and understood the operation, lubrication, maintenance and repair information.

Operations that may cause product damage are identified by NOTICE labels on the product and in this publication.

DAEWOO cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are therefore not all inclusive. If a tool, procedure, work method or operating technique not specifically recommended by DAEWOO is used, you must satisfy yourself that it is safe for you and others. You should also ensure that the product will not be damaged or made unsafe by the operation, lubrication, maintenance or repair procedures you choose.

The information, specifications, and illustrations in this publication are on the basis of information available at the time it was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service given to the product. Obtain the complete and most current information before starting any job. DAEWOO dealers have the most current information available.

Electric Systems

1

E/G Starting & Stop System

Electric Systems

3

E/G Starting & Stop System

– 12Volts, 100AH battery with 750 Cold-Cranking Amps.

– The start motor is rated 2.0 kW.

1. E/G Starting & Stop System (440Plus)

Electric Systems

4

Preheating & Charging System

– The Preheat Controller controls the operation of the Glow Plugs to give better starts to a cold engine.

The controller will turn ON the Preheat Lamp for 5 seconds and also activate the Preheat Relay for 7 seconds.

According to the temperature which is sensed by Thermal Sender, the time of After Heating will be set after starting.

2. Preheating & Charging System (440Plus)

3. Instrument Panel Layout (440Plus)

15

3

2

4

5

E

11

14

D

1

B 12

10 8

6

9

7

13

A

Instrument Panel-LH

Instrument Panel-RH

A) On switch B) OFF switch C) Green indicator light D) detent switch “ON” E) Detent switch “OFF”

1) Key Switch 2) Water temperature warning light 3) Engine oil pressure warning light 4) Charge warning light 5) HST oil temperature warning light 6) HST pressure warning light 7) Oil filter warning light 8) Warning light(Yellow) 9) Stop light(Red) 10) Sediment 11) Light switch 12) Pre-heat light 13) Parking brake light 14) Fuel gage 15) Hour meter

Electric Systems

C

NOTE : Reter to MONITORING SYSTEM

5

Instrument Panel Layout

4. Monitoring System (440Plus) Electric Systems

6

Monitoring System

Electric Systems

7

Pushing button(C)

Pushing button(A)

Pushing button(C)

Pushing button(A)

forward control

panel

Pushing switch(E)

Pushing switch(D)

Pushing switch(D)

Pushing switch(D)

Either way

Pushing switch(E)

Pushing switch(E)

Pushing switch(E)

NOTE : Refer to Schematic-Elec for Thumb Control.

control

Detent

control

Momentary

switch(D,E) on

forward control

panel

Detent rocker

Button(A,C)on

Thumb button

“R2” relay “D1” relay “D2” relay

of button, -After that releasing button

-

“R1” relay

right hand side

Either way

“ON” relay

“D2” relay

releasing button -Keep depressing

“F2” relay “D1” relay

of button,

“F1” relay

left handside -After that

“ON” relay

“D2” relay

“D1” relay

“ON” relay

-Keep depressing

Neutral

-

“R2” relay

of button Either way

“R1” relay

right hand side

“F2” relay

of button “ON” relay

“F1” relay

left hand side Keep kepressing

“ON” relay

“ON” relay

Keep depressing

Neutral

lever

on right control

operation

mode

Operation by operator

Relay

Operation

-

REV solenoid

FWD solenoid

-

-

REV solenoid

FWD solenoid

-

-

Spool-in

Spool-out

-

-

Spool-in

Spool-out

-

line port on

-

Upper side

Down side

-

-

Upper side

Down side

-

boom(left side)

of hydraulic control valve

solenoid activation

Flow out of attachment

Attachment spool motion

spool

Attachment

5. Operation of the related parts in momentary control & detent control (440Plus)

- Relay, solenoid valve, spool motion of control valve and direction of pump flow to attachment quick coupler port

Operation of the related parts in momentary control & detent control

Electric Systems

8

Thumb Control

6. Thumb Control (1760XL(DSL802-D430))

7. Lights and Options • Dual front and single rear area flood lights for standard.

• Available Options • Strobe light • Horn • Back up buzzer • Heater • Cigar lighter NOTE : Refer to WIRING SCHEMATIC - ELEC.

Electric Systems

9

LIGHTS and OPTIONS

8. Item Descriptions and Functions (440Plus)

4) Charge warning Light

1) Key Switch

• The light turns on when trouble occurs in the charging system.

2) Water Temperature Warning Light

5) HST Oil temperature Warning Light

• The light turns on when the temperature of the engine cooling water exceeds 110˚C (230 ˚F).

• The light turns on when the temperaturre of the hydraulic oil to drive HST goes up to 100˚C (212 ˚F).

3) Engine Oil Pressure Warning Light

6) HST Pressure Warning Light

• The light turns on when the engine oil pressure is below 0.5 kg/cm2(15 psi).

• The light turns on when the pressure of the HST pump oil falls below 6.0 kg/cm2 (85 psi).

Electric Systems

10

Item Descriptions and Functions

7) Oil filter warning Light

10) Water separator warning Light

• If the oil filter becomes clogged, the light turns on.

• The light turns ON when the water exceeds 70cc in the fuel filter.

8) Warning Light

11) Light Switch

• The light turns on simultaneously with Charge HST oil temperature, HST pressure and oil filter warning lights.

• Step 1 : Two front lights turn on.

• Step 2 : Two front lights and one rear light turn on simultaneously.

9) Stop Light

12) Pre-heat Light

• The light turns on simultaneously with water temperature and engine oil pressure warning lights.

• When the key is turned to the “IGN” position, the glowplug relay turns on this light.

Electric Systems

11

Item Descriptions and Functions

13) Parking Brake Light

Buzzer

• Raising the hand lever, the parking brake is engaged and the light turns on.

• The buzzer is activated simultaneously with water temperature and engine oil pressurre warning lights.

14) Fuel Gage

• Fuel gage shows the amount of fuel in the fuel tank.

15) Hour meter

• Hour meter indicates the total hours of vehicle operating.

Electric Systems

12

Item Descriptions and Functions

9. Trouble Shooting

9.2. Trouble Shooting Guide

9.1. Test Equipment

NOTE 1 : The DSL has no electrical shutdowns, only visual and auditory indicators.

The following items should be sufficient to allow you to perform most electrical troubleshooting operations on the electrical system.

NOTE 2 : The lighting, instrument panel, and start (key switch) fuses (and horn fuse-optional, if equipped) located in the right-side instrument panel are all 15-amp tube-type fuses.

• Volt/ohmmeter (Multimeter) • Jumper wires (variety of lengths) with alligator clip ends • Needle tips • External 12-volt source • Wiring diagrams

Symptom Discharged battery

Engine does not crank

The following troubleshooting guide presents possible causes and actions in a logial order from simplest/most likely to more complex/less likely (more drastic). For any symptom, if a given action does not identify the problem, proceed to the next action.

Possible Cause

Action

Loose/damaged alternator belt.

Tighten/replace belt.

Loose/dirty connections.

Adjust/clean clamps, posts.

Battery faulty.

Replace battery.

Alternator faulty.

Check or replace.

Battery may be discharged.

Check battery condition.

Start fuse may be blown.

Check fuse in instrument panel.

Problem in neutrl safety

Wiggle drive levers while trying to

mechanisms.

start. If engine starts, adjust neutral switches and/or centering control(s).

Neutral switch(es) may be faulty.

Jumper neutral switch(es) one at a time. If engine starts, replace neutral switch(es).

Start relay may be faulty.

Jumper start relay. If engine starts, replace start relay.

Engine cranks but does not start

Glow plug does not work

Loader is out of fuel.

Check fuel tank.

Engine has starting problem not

Check engine. See section

related to electrical system.

Engine in this manual.

Alternator may be faulty.

Check alternator.

Wiring problem.

Check glow plug wiring.

Glow plug relay may be faulty.

Check wiring to relay. Jumper relay.

If glowplug works, replace relay.

Instrument panel indicator lights do

Glow plug elements(s) may be

Check elements. If problems found,

faulty.

replace glow plug.

Fuse may be blown

Check/replace fuse in instrument panel.

not come on or give faulty indications.

Individual panel lights do not

Control unit may be faulty

Replace control unit.

Bulbs may be faulty.

Check/replace bulbs.

come on.

Wiring to light may be faulty.

Check individual wiring.

Repair faulty connections or replace wires.

Electric Systems

13

Trouble shooting

Symptom Fuel gage does not work or gigves

Possible Cause Sender wiring may be faulty.

Action Check wiring between meter and

faulty indication (other instrument

instrument panel. Check sender

panel functions are OK)

ground.

Gage may be faulty.

Replace gage.

Meter wiring may be faulty.

Check meter wiring.

are OK).

Rear or front flood lights do not

Meter may be faulty.

Replace meter.

Fuse may be blown in instrument

Check/replace fuse in instrument

turn on.

panel.

panel.

Bulb(s) may be burned out.

Check/replace bulbs.

Wiring may be faulty.

Check connections and wires.

Hour meter does not register hours (other instrument panel functions

Check connections in cab wiring connector.

Electric Systems

14

Trouble shooting

1

2