Page 1

9 4 3

Service Manual

6570008 (4–86)

Printed in U.S.A.

© Melroe Company 1986


MAINTENANCE SAFETY WARNING

Instructions are necessary before operating or servicing machine. Read and understand the Operation & Maintenance Manual, Operator’s Handbook and signs (decals) on machine. Follow warnings and instructions in the manuals when making repairs, adjustments or servicing. Check for correct function after adjustments, repairs or service. Untrained operators and failure to follow W-2003-0903 instructions can cause injury or death.

Safety Alert Symbol: This symbol with a warning statement, means: “Warning, be alert! Your safety is involved!” Carefully read the message that follows.

CORRECT

CORRECT

CORRECT

B-10731a

B-12365

B-7469

Never service the Bobcat SkidSteer Loader without instructions.

Use the correct procedure to lift or lower operator cab.

Cleaning and maintenance are required daily.

WRONG

WRONG

WRONG

B-11799

B-15231

B-15280

Have good ventilation when welding or grinding painted parts. Wear dust mask when grinding painted parts. Toxic dust and gas can be produced. Avoid exhaust fume leaks which can kill without warning. Exhaust system must be tightly sealed.

Disconnecting or loosening any hydraulic tubeline, hose, fitting, component or a part failure can cause lift arms to drop. Do not go under lift arms when raised unless supported by an approved lift arm support device. Replace it if damaged.

Never work on loader with lift arms up unless lift arms are held by an approved lift arm support device. Replace if damaged. Never modify equipment or add attachments not approved by Bobcat Company.

WRONG

WRONG

WRONG

B-6590

B-6580 B-16102

B-6589 B-16102

Stop, cool and clean engine of flammable materials before checking fluids. Never service or adjust loader with the engine running unless instructed to do so in the manual. Avoid contact with leaking hydraulic fluid or diesel fuel under pressure. It can penetrate the skin or eyes. Never fill fuel tank with engine running, while smoking or when near open flame.

Keep body, jewelry and clothing away from moving parts, electrical contact, hot parts and exhaust. Wear eye protection to guard from battery acid, compressed springs, fluids under pressure and flying debris when engines are running or tools are used. Use eye protection approved for type of welding. Keep rear door closed except for service. Close and latch door before operating the loader.

Lead-acid batteries produce flammable and explosive gases. Keep arcs, sparks, flames and lighted tobacco away from batteries. Batteries contain acid which burns eyes or skin on contact. Wear protective clothing. If acid contacts body, flush well with water. For eye contact flush well and get immediate medical attention.

Maintenance procedures which are given in the Operation & Maintenance Manual can be performed by the owner/ operator without any specific technical training. Maintenance procedures which are not in the Operation & Maintenance Manual must be performed ONLY BY QUALIFIED BOBCAT SERVICE PERSONNEL. Always use genuine Bobcat replacement parts. The Service Safety Training Course is available from your Bobcat dealer. MSW01-0805


FOREWORD This manual is for the Bobcat loader mechanic. It provides necessary servicing and adjustment procedures for the loader and its component parts and systems. Refer to the Operation & Maintenance Manual for operating instructions, starting procedure, daily checks, etc. A general inspection of the following items must be made after the loader has had service or repair: 1. Check that the ROPS/FOPS (including sidescreens) is in good condition and is not modified.

9. Enclosure door latches must open and close freely.

2. Check that ROPS mounting hardware is tightened and is Melroe approved.

10. Bob–Tach wedges and linkages must function correctly and be in good condition.

3. The seat belt must be correctly installed, functional and in good condition.

11. Safety treads must be in good condition.

4. The seat bar and pedal interlocks must be correctly adjusted, clean and lubricated.

12. Check for correct function of indicator lamps (Optional on some models).

5. Machine signs must be legible and in the correct location.

13. Check hydraulic fluid level, engine oil level and fuel supply.

6. Steering levers, and foot pedals must return to neutral.

14. Inspect for fuel, oil or hydraulic fluid leaks.

7. Check for correct function of the work lights and travel lights.

15. Lubricate the loader.

8. The parking brake must . function correctly.

16. Check the condition of the battery and cables.

Revised Feb. 94 0

943 Loader Service Manual


17. Inspect the air cleaner for damage or leaks. Check the condition of the element.

18. Check the electrical charging system.

19. Check tires for wear and pressure.

20. Inspect for loose or broken parts or connections.

21. Operate the loader and check all functions.

22. Check for any field modifications not completed.

Recommend to the owner that all necessary corrections be made before the machine is returned to service.

1–

943 Loader Service Manual


CONTENTS SERIAL NUMBER LOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i DELIVERY REPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i BOBCAT LOADER IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii PREVENTIVE MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–1 HYDRAULIC SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–1 HYDROSTATIC SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–1 DRIVE SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–1 MAIN FRAME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–1 ELECTRICAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–1 ENGINE SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–1 TECHNICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8–1

PREVENTIVE MAINTENANCE

HYDRAULIC SYSTEM

HYDROSTATIC DRIVE SYSTEM

DRIVE SYSTEM

MAIN FRAME

ELECTRICAL SYSTEM

ENGINE SERVICE

TECHNICAL DATA

ALPHABETICAL INDEX

2

943 Loader Service Manual


SERIAL NUMBER LOCATIONS

A

Always refer to the correct serial number when ordering parts or making repairs. LOADER SERIAL NUMBER The loader serial number plate is located on the inside of the left upright, above the grill [A]. Explanation of loader Serial Number: XXXX

XXXX Production Sequence (Series)

Model, Engine Version B–07425

B

ENGINE SERIAL NUMBER The engine serial number is on the engine block, above the fuel injection pump [B].

B–07424

DELIVERY REPORT

C

The Delivery Report must be filled out by the dealer and signed by the owner or operator when the bobcat loader is delivered. An explanation of the form must be given to the owner. Be sure that it is filled out completely before you sign it [C].

Revised Nov. 87

–i–

943 Loader Service Manual


BOBCAT LOADER IDENTIFICATION

943ServiceManual#6570008–ForewordSection

Front Lights

Seat Bar

Grab Handles

Operator Seat

Steering Levers

Tilt Cylinders Safety Treads

Auxiliary Hydraulic Quick Couplers

Bucket {

Steps Operator Cab (ROPS & FOPS) D

Uprights

Lift Arm Grill

Lift Cylinder

Rear Lights

Rear Door Tires *

B–11949 B–11957

* TIRES – Flotation tires are shown. The Bobcat loader is base–equipped with standard tires. { BUCKET – Several different buckets are available for the Bobcat loader. • ROPS, FOPS – Roll–Over Protective Structure, Falling Object Protective Structure, per SAE J1040 or SAE J1043. The Bobcat loader is base–equipped with a standard operator cab as shown.

Revised Nov. 87

–ii–

943 Loader Service Manual


PREVENTIVE MAINTENANCE Page Number

PREVENTIVE MAINTENANCE

AIR CLEANER Replacement Of Air Cleaner Element . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–10 COLD TEMPERATURE STARTING Starting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–16

COOLING SYSTEM Checking Coolant Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–13 Removing Coolant From Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 1–13 ELECTRICAL SYSTEM Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–14 Electrical System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–14 Using An Extra Battery (Jump Starting) . . . . . . . . . . . . . . . . . . . . . . . . . . 1–15 ENGINE OIL AND FILTER Replacement Of Engine Oil And Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–12 FINAL DRIVE CHAINCASE Checking And Adding Chaincase Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–19 FUEL SYSTEM Filling The Fuel Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–11 Removing Water From The Fuel Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 1–11 HYDRAULIC/HYDROSTATIC SYSTEM Checking And Adding Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–17 Replacing Hydraulic/Hydrostatic Filters . . . . . . . . . . . . . . . . . . . . . . . . . . 1–17 LIFT ARM SUPPORT DEVICE Installing The Lift Arm Support Device . . . . . . . . . . . . . . . . . . . . . . . . . . 1–4 LIFTING AND BLOCKING THE LOADER Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2 LOADER LUBRICATION Lubrication Of The Loader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–20 OPERATOR CAB Operator Cab Air Seals (S/N 11999 & Below) . . . . . . . . . . . . . . . . . . . . Cleaning Rear Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lowering The Operator Cab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Raising The Operator Cab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1–6 1–7 1–5 1–5

PIVOT PIN Checking Pivot Pin Retainer Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–21 REAR DOOR Adjusting The Door Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–9 Opening The Rear Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–9 REAR GRILL Opening The Rear Grill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–10 REMOTE START SWITCH Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–22 Continued On Next Page Revised April 92

–1––1–

943 Loader Service Manual


PREVENTIVE MAINTENANCE Page Number SEAT BAR SYSTEM Inspecting The Seat Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–7 Servicing The Seat Bar System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–8 SERVICE SCHEDULE Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–1 SPARK ARRESTOR MUFFLER Cleaning The Spark Arrestor Muffler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–18 Cleaning Exhaust Purifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–18 STEERING CONTROL LIMITER Lubricating The Steering Control Limiter . . . . . . . . . . . . . . . . . . . . . . . . . 1–22 TIRE INSPECTION AND ROTATION Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–19 Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–19 Wheel Nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–20 TRANSPORTING THE BOBCAT LOADER Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–3 TOW VALVES Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–3

–1–0–

943 Loader Service Manual


SERVICE SCHEDULE This service schedule is a guide for correct maintenance of the Bobcat loader that must be done regularly. Always use these service intervals unless very hot, cold, dusty or corrosive operating conditions make it necessary to increase the frequency of service. Failure to do so can cause damage to the machine.

Instructions are necessary before operating or servicing machine. Read Operation & Maintenance Manual, Handbook and signs (decals) on machine. Follow warnings and instructions in the manuals when making repairs, adjustments or servicing. Check for correct function after adjustments, repairs or service. Failure to follow instructions can cause injury or death.

W–2003–1089

ITEM Engine Oil Engine Air Cleaner Engine Coolant System Tires Seat Belt, Seat Bar & Pedal Interlocks Exhaust System Safety Signs (Decals) & Safety Treads Bob–Tach & Lower Tilt Cylinder Pivot Hydraulic/Hydrostatic Fluid Engine Fuel Filter Operator Cab Lift & Tilt Pedals Area Wheel Nuts Hydraulic Fluid, Tubelines & Hoses Alternator Drive Belt Controls & Brakes Loader Pivot Areas & Bob–Tach Wedges Spark Arrestor Muffler Engine Oil & Filter Batteries Chaincase Belt Drive Tightener

SERVICE REQUIRED

A

A

8–10 50 100 150 250 500 1000

Check the oil level & add oil as needed. Check restriction indicator. See Page 1–10 for the correct procedure to service the air filter elements. Clean debris from cooling fins & rear grill. Check for damaged tires & correct air pressure. Check the condition of seat belt. Check the seat bar & pedal interlocks for correct operation. Check condition of system. See Page 1–6 for more information. Check for damaged signs & safety treads. Replace the safety signs & safety treads if worn or damaged. Add grease to the fittings until extra grease shows. Check the fluid level in the reservoir & add fluid as needed. Remove water from filter. Check the fastening bolts, washers & nuts. Check the condition of the cab. Remove clean–out caps. Remove dirt & debris from the pedal area. LCheck for loose wheel nuts. Tighten to correct torque if loose. Check the fluid level & add as needed. Check for damage & leaks & replace as needed. Check the tension & adjust as needed. Check operation & adjust as needed. Add grease to the fittings until extra grease shows. Remove the plug & clean the spark chamber. Replace the engine oil & the filter. Check the water level. Check battery cables for corrosion. Check that the battery cables are tight. Check covers. Check fluid level & add as needed. JCheck gap at rod nuts. Correct gap is 0.060–0.120” (1,5–3,0 mm). Grease pivot as needed. Replace the filter elements & in–line fuel filters. DReplace filter elements.

Seat Bar Engine Fuel Filter Hydraulic/Hydrostatic Filters Hydraulic/Hydrostatic Replace the breather cap. Fluid Reservoir Chaincase Replace the fluid. Hydraulic Fluid Reservoir Replace the hydraulic/hydrostatic fluid. L D J A

Check wheel nut torque every 8 hours for the first 24 hours of operation. Replace elements sooner if warning light comes ON. Check every 8 hours for the first 40 hours of operation. Or every 12 months.

Revised April 92

–1–1–

943 Loader Service Manual


PREVENTIVE MAINTENANCE

A

Instructions are necessary before operating or servicing machine. Read Operation & Maintenance Manual, Handbook and signs (decals) on machine. Follow warnings and instructions in the manuals when making repairs, adjustments or servicing. Check for correct function after adjustments, repairs or service. Failure to follow instructions can cause injury or death [A].

W–2003–0797

B–07023

Wear safety glasses to prevent eye injury when any of the following conditions exist: • When fluids are under pressure. • Flying debris or loose material is present. • Engine is running. • Tools are being used.

W–2019–1285

LIFTING AND BLOCKING THE BOBCAT LOADER

B

Procedure Always park the loader on a level surface.

Put jackstands under the front axles and rear corners of the frame before running the engine for service. Failure to use jackstands can allow the machine to fall or move and cause injury or death.

B–08109

W–2017–0286

C Lower the lift arms, stop the engine. Put the floor jack under the rear of the loader. Lift the rear of the loader and install jackstands [B]. Put the floor jack under the front of the loader. Lift the front of the loader and install jackstands under the axle tubes [C]. NOTE: Make sure the jackstands do not touch the tires.

B–08108

Revised April 92

–1–2–

943 Loader Service Manual


TRANSPORTING THE BOBCAT LOADER

A

Procedure

Adequately designed ramps of sufficient strength are needed to support the weight of the machine when loading onto a transport vehicle. Wood ramps can break and cause personal injury.

W–2058–0494 B–11955

A loader with an empty bucket or no attachment must be driven backward onto the transport vehicle [A].

B

Lower the lift arms and bucket onto the transport vehicle [B]. Stop the engine. Engage the parking brake. To prevent the loader from moving during sudden stops or going up and down slopes, install tie–down chains as follows:

B–11956

Fasten chains to the uprights as shown in figure [C].

C

B–11958

Fasten chain to the front of the loader as shown in figure [D].

D

TOW VALVES Procedure The loader can be moved for a short distance when the tow valves are open. (See Page 3–29, Fig. [C].) Turn the two tow valves open one half turn. NOTE: After moving the loader with the tow valves open, make sure the tow valves are closed and tight because they have a direct effect on the operation of the loader drive system. B–07411

Revised April 92

–1–3–

943 Loader Service Manual


LIFT ARM SUPPORT DEVICE Installing The Lift Arm Support Device NOTE: Maintenance or service work can be done with the lift arms lowered. Put jackstands under the rear corners of the loader before raising the operator cab or lift arms. One person must stay in the operator’s seat, with the seat belt fastened and the seat bar lowered, while the second person installs the lift arm support device.

Never work on a machine with the lift arms up unless the lift arms are secured by a lift arm support device. Failure to use an approved lift arm support device can allow the lift arms or attachment to fall and cause injury or death. W–2059–0991

Start the engine and raise the lift arms all the way up. Have the second person install the lift arm support device [A]. The lift arm support device must be tight against the lift cylinder rod. Lower the lift arms slowly until the support device is held between the lift arm and the lift cylinder.

A

B–07437

Revised April 92

–1–4–

943 Loader Service Manual


OPERATOR CAB

A

Raising The Operator Cab

B–07705

AVOID INJURY Cylinders for raising and lowering operator cab have gas under pressure. Do not open cylinder. Only qualified service personnel can remove the cylinder. W–2112–0987

B–07495

Stop the loader on a level surface. Lower the lift arms fully. If the lift arms must be up while raising the operator cab, install a lift arm stop before raising the cab. (See Page 1–4.)

B

Before the cab or the lift arms are raised for service, jackstands must be put under the rear corners of the frame. Failure to use jackstands can allow the machine to tip backward causing injury or death.

B–07491

W–2014–0895

C Remove the two front fasteners of the operator cab [A]. If the lift arms are down, stand on the lift arm cross member safety tread. Lift on the top of the operator cab and grab handle and then lift on the bottom of the operator cab, until it is all the way up [B]. If the lift arms are held up by a lift arm stop, stand on the loader frame safety treads. Lift on the top of the operator cab and the grab handle and then lift on the bottom of the operator cab, until it is all the way up [C]. B–07492

Lowering The Operator Cab Stand on the lift arm cross member or loader frame safety tread and slowly lower the operator cab by using the bottom of the cab and the grab handle [B] & [C].

Both sets of fasteners at the front of the operator cab (ROPS) must be assembled as shown in this manual. Failure to secure ROPS correctly can cause injury or death. W–2005–1189

Revised Nov. 87

–1–5–

943 Loader Service Manual


OPERATOR CAB (Cont’d)

A

Never modify the operator cab or safety equipment or use attachments that are not approved by Melroe Company. Modifications or unapproved attachments can cause injury or death.

W–2035–1285 B–08106

Operator Cab Air Seals (S/N 11999 & Below) The rubber and foam seals between the engine compartment and the operator cab must be tight.

B

Higher temperatures and pressure in the engine compartment can force air into the cab if the seals are not tight. Check for air leaks into the cab at the following locations: 1. Rubber boots around the lower end of the steering levers [A]. 2. Foam insulation under seat plate [B]. 3. Seals between operator cab and frame [B]. B–08107

4. Make sure clean out tubes are correctly installed. The exhaust system must be tight to avoid leaks of exhaust fumes into the engine compartment. Never use a loader with a defective exhaust system.

When an engine is running in an enclosed area, fresh air must be added to avoid concentration of exhaust fumes. If the engine is stationary, vent the exhaust outside. Exhaust fumes contain odorless, invisible gases which can kill without warning. W–2050–1285

Revised Nov. 87

–1–6–

943 Loader Service Manual


OPERATOR CAB (Cont’d)

A

Cleaning Rear Window, Optional Front Door And Enclosure Use only approved cleaners on the windows of the loader [A]. Never use cleaners that have abrasive. Do not let cleaning solutions dry on the window. Cleaning solutions must be thoroughly rinsed with water. Do not use razor blades or other sharp objects to scrape the window.

B–07469

SEAT BAR SYSTEM

B

Description The seat bar system has a pivoting seat bar with arm rests and has spring loaded interlocks for the lift and tilt control pedal [B]. The operator controls the use of the seat bar, the seat bar in the down position helps to keep the operator in the seat, also the interlocks require the operator to lower the seat bar in order to operate the foot pedal controls. When the seat bar is up, the lift and tilt pedals are locked when returned to the neutral position. Inspection Of The Seat Bar System Sit in the seat and fasten the seat belt. Engage the parking brake.

B–11970

Pull the seat bar fully down. Start the engine. Operate each foot pedal to check both the lift and tilt functions. Raise the lift arms until the bucket is about 2 feet (600 mm) off the ground. Raise the seat bar. Try to move each foot pedal. Pedals must be firmly locked in neutral position. There must be no motion of the lift arms or tilt (bucket) when the pedals are pushed. Pull the seat bar down, lower the lift arms and place the bucket flat on the ground. Stop the engine. Raise the seat bar and operate the foot pedals to be sure that the pedals are firmly locked in the neutral position. Unbuckle the seat belt.

Revised April 92

–1–7–

943 Loader Service Manual


SEAT BAR SYSTEM (Cont’d)

A

Servicing The Seat Bar System See the SERVICE SCHEDULE Page 1–1 for the correct service intervals.

Clean & Lubricate

Clean any debris or dirt from moving parts [A] [B]. Apply general purpose grease to seat bar pivots at each side of the cab [A]. If seat bar system does not function correctly when inspected, check for free movement of each linkage part. Check for excessive wear. Adjust the pedal control linkage. Replace parts that are worn or damaged. Use only genuine Melroe replacement parts.

B–07387

B

AVOID INJURY OR DEATH The seat bar system must lock the lift and tilt control pedals in neutral when the seat bar is up. Service the system if pedals do not lock correctly.

Clean

W–2105–1285

B–11970

Revised April 92

–1–8–

943 Loader Service Manual


REAR DOOR

A

Opening Rear Door

AVOID INJURY OR DEATH Stop, cool and clean engine of flammable material. Never service or adjust loader with engine running unless instructed to do so in manual.

W–2061–0887

B–07413

B

Pull up on the handle [A]. Turn the handle to release the latch and pull the rear door open [B].

Keep the rear door closed when operating the machine. Failure to do so could seriously injure a bystander. W–2020–1285

B–07414

C

Adjusting The Door Latch Loosen the set screw (inset) and nut (Item 1) [C]. Adjust the bolt (Item 2) [C] so the top and bottom corners of the door touch the loader frame with the door closed and the handle in the latched position.

B–05772

NOTE: When the latch is adjusted correctly, it will take approximately 50 lbs. (23 kg) to push the handle into the locked position.

1 2

Turn the bolt so that the roll pin is horizontal [C].

B–07481

Tighten the set screw. Tighten the nut (Item 1) [C] to 65–70 ft. lbs. (88–95 Nm) torque. Lubricate the wear surfaces of the latch.

Revised Nov. 87

–1–9–

943 Loader Service Manual


REAR GRILL

A

Opening The Rear Grill

AVOID INJURY OR DEATH Stop, cool and clean engine of flammable material. Never service or adjust loader with engine running unless instructed to do so in manual.

W–2061–0887

B–07420

Open the rear door and raise the rear grill [A]. The rear grill is held open by a gas cylinder. Raise the rear grill to clean debris from the oil cooler and radiator. Raise the oil cooler for access to the radiator.

B

2

AIR CLEANER Replacement Of The Air Cleaner Element NOTE: Before replacing the filter element, push the reset button at the restriction indicator. Start the engine and run at full RPM. If the reading is less than 22 in. H20, do not replace the filter element. Clean the evacuator (Item 1) [B] every day. Check all hoses and connections for leaks.

1

Start the engine and check the restriction indicator (Item 2) [B]. If the reading is more than 22 in. H20, replace the outer filter (Item 1) [C].

B–07421

C

Replace the inner filter element (Item 2) [C] every third time the outer element is replaced or when the restriction indicator shows 15 in. H20 after the outer element has been replaced.

2

3

NOTE: Make sure the seal washer (Item 3) [C] is under the wing nut when replacing the filter element. Push the reset button at the restriction indicator.

1

3

B–07509

Revised Nov. 87

–1–10–

943 Loader Service Manual


FUEL SYSTEM

A

Filling The Fuel Tank Use number 2 diesel fuel. During very cold temperatures, use number 1 fuel. Remove the fuel fill cap (Item 1), add fuel as needed [A].

1

Stop and cool the engine before adding fuel. NO SMOKING! Failure to obey warnings can cause an explosion or fire.

B–11953

W–2063–0887

B

WRONG

Fill the fuel tank only in an area with good ventilation and no open flames or sparks [B]. Always use clean fuel and container to add fuel to the fuel tank.

B–07468

Removing Water From The Fuel Filter

C

Loosen the thumb screw (Item 1) [C] on the bottom of the filter. Drain the water into a container. Tighten the thumb screw after the water has been removed from the filter.

1

See Section 7, for replacement of fuel filter elements and remove air from the fuel system.

2

Revised April 92

–1–11–

B–07426

943 Loader Service Manual


ENGINE OIL AND FILTER

A

943ServiceManual#6570008–PreventiveMaintenanceSectionPart1of2

Replacement Of Engine Oil And Filter See the SERVICE SCHEDULE Page 1–1 for the correct service interval.

1

Check the oil level every 8–10 hours of operation (Item 1) [A].

B–07427

B

Use the recommended engine oil [B]. Run the engine until warm. Stop the engine.

RECOMMENDED SAE VISCOSITY NUMBER (LUBRICATION OILS FOR ENGINE CRANKCASE) C°–34 –29

–23 –18

–13

–7

–1

+4

+10 +15

+21

+27 +32 +38

+43

+49

+54 +60

SAE 40 or 20W–50

SAE 10W–30

SAE 15W–40

SAE 5W–30 SAE 30

SAE 20W/20

SAE 10W

F°–30 –20

–10

0

+10

+20 +30

+40 +50 +60

+70

+80 +90 +100 +110 +120 +130 +140

TEMPERATURE RANGE ANTICIPATED BEFORE NEXT OIL CHANGE (GASOLINE: USE API CLASSIFICATION SE OR SF) (DIESEL: USE API CLASSIFICATION CC, CD OR CE)

PI–02358

Remove the filter (Item 1) [C] and drain hose cap (Item 2) [C].

C

Clean the contact surface of the filter housing. Put clean oil on the gasket of the new filter. Install the oil filter and hand tighten only. Install the drain hose cap. Fill the engine to the correct capacity (See Specification Section for the correct capacity).

1

Start the engine. Check for leaks at the oil filter. Stop the engine.

2

Check the oil level, add oil as needed to bring the oil level to the top mark on the dipstick. B–07428

Revised April 92

–1–12–

943 Loader Service Manual


COOLING SYSTEM

A

Checking Coolant Level

1

Check the coolant level in the recovery tank when the engine is cool. Coolant must be at the full mark on the recovery tank (Item 1) [A].

2

Lift the oil cooler and use air or water pressure to remove debris from the top of the radiator. Removing The Coolant From The Cooling System B–07430

B Do not remove radiator cap when the engine is hot. You can be seriously burned. W–2070–1285

Raise the rear grill and remove the radiator cap (Item 2) [A].

PI–07483

Open the drain valve (Item 1) [C] at the engine block. Use a hose to direct the coolant into a container. Do not let coolant flow into the engine compartment.

C

Close the valve after all the coolant is removed from the cooling system. Pre–mix ethylene glycol anti–freeze (50%) and water (50%). Fill the radiator with the coolant mixture. Install the radiator cap. Add coolant mixture to the FULL mark on the recovery tank.

1

B–07457

Revised Nov. 87

–1–13–

943 Loader Service Manual


ELECTRICAL SYSTEM

A

Description

1

The Bobcat loader has a 12–volt, negative ground charging system.

2

There are two fuses (Item 1) [A] in the instrument panel to protect the electrical system. A blown fuse indicates a system overload. Check for a broken wire or a short in the electrical system before starting the engine. The engine and hydraulic/hydrostatic warning lights (Item 2) [A] will come ON when the key switch is turned ON. When the engine is started, the lights must go OFF. Stop the engine and correct the problem, if the lights do not go OFF.

B–07524

B

Electrical System Maintenance Water and Baking Soda Solution

Check the condition of the battery terminals and cable ends. Use a sodium bicarbonate (baking soda) and water solution to remove any acid or corrosion from the terminals or battery cable ends. Put grease on the cable ends to prevent corrosion. Check the condition of all the electrical wires.

A–02741

Revised Nov. 87

–1–14–

943 Loader Service Manual


ELECTRICAL SYSTEM (Cont’d) Using An Extra Battery (Jump Start) If it is necessary to use an extra battery to start the engine, BE CAREFUL! There must be one person in the operator’s seat and one person to connect and disconnect the battery cables. The extra battery must be the same voltage as the loader battery.

Batteries contain acid which burns eyes and skin on contact. Wear goggles, protective clothing and rubber gloves to keep acid off body.

1. Turn the ignition to the OFF position. 2. Connect the first jumper cable (Item 1) [A] to the positive (+) terminal of the extra battery and to the solenoid terminal (Item 2) [A] of the starter.

In case of acid contact, wash immediately with water. In case of eye contact get prompt medical attention and wash eye with clean, cool water for at least 15 minutes.

NOTE: Never connect the negative (–) cable to the negative (–) terminal of the battery.

If electrolyte is taken internally drink large quantities of water or milk! DO NOT induce vomiting. Get prompt medical attention.

3. Connect the second jumper cable (Item 3) [A] to the negative (–) terminal of the extra battery and to the engine mounting frame (Item 4) [A].

W–2065–1296

4. Keep the jumper cables away from moving parts. 5. Start the engine (Also See COLD TEMPERATURE STARTING, Page 1–16). 6. Immediately remove the negative (–) cable (Item 4) [A] from the engine frame. 7. Remove the positive (+) cable from the starter.

Damage to the alternator can occur if:

• Engine is operated with battery cables disconnected.

• Battery cables are connected when using a •

fast charger or when welding on the loader. (Remove both cables from the battery.) Extra battery cables (booster cables) are connected wrong.

A

I–2023–1285

2 4

+

– 3

1 B–08066

Revised Nov. 87

–1–15–

943 Loader Service Manual


COLD TEMPERATURE STARTING

A

Starting Procedure To make starting easier if the temperature is below 32°F. (0°C.), use the following procedure: 1. Replace the engine oil with the correct type and viscosity for the anticipated starting temperature. (See Page 1–12.) 2. Make sure the battery is at full charge. 3. Install a coolant heater on the engine. To start the engine, use the following procedure: Turn the key switch to the START position, and start to turn the engine.

B–07566 6593388

Push the quick–start button. This will fill the fluid dispenser [A]. Release the button. This dispenses the starting fluid into the engine intake manifold. The sound of the engine should change. Keep cranking the engine for a few seconds. This either starts the engine or uses the starting fluid so that it does not accumulate in the engine. Repeat the above steps. Always keep cranking the engine for a few seconds to avoid too much starting fluid in the engine. If the engine does not start after repeating the above steps three times, correct deficiencies such as: empty starting fluid can, wrong fuel, too heavy viscosity oil, low charge at battery, etc. NOTE: The starting fluid contains ether which is a flammable and explosive gas. Arcs, sparks, flames and lighted tobacco must be kept away from the ether to avoid explosions and fire. Let the engine run for a few minutes to warm the engine and hydrostatic fluid before operating the loader. During very cold temperatures (0°F. –23°C. and below), let the engine run for at least five minutes.

When the temperature is below –20°F (–30°C), hydrostatic oil must be warmed before starting. The hydrostatic system will not get enough oil at low temperatures and will be damaged. Park the machine in an area where the temperature will be above 0°F (–18°C) if possible. I–2007–1285

Revised Nov. 87

–1–16–

943 Loader Service Manual


HYDRAULIC AND HYDROSTATIC SYSTEM

A

See Section 2 and 3 for the complete description of the Hydraulic and Hydrostatic System and Flow Charts.

Diesel fuel or hydraulic fluid under pressure can penetrate skin or eyes, causing serious injury or death. Fluid leaks under pressure may not be visible. Use a piece of cardboard or wood to find leaks. Do not use your bare hand. Wear safety goggles. If fluid enters skin or eyes, get immediate medical attention from a physician familiar with this injury.

B–07497

B

W–2072–0496

Checking And Adding Fluid The loader must be level, lift arms all the way down and Bob–Tach rolled all the way back. Check the fluid level [B]. Add fluid as necessary (See Section 8 for correct specification for the hydraulic fluid). B–07423

B–07482

Replacing The Hydraulic/Hydrostatic Filters

C

See the SERVICE SCHEDULE Page 1–1 for correct service procedure or replace the filters if the warning lights come ON during operation. Remove the hydraulic filter (Item 1) [C] and hydrostatic filter (Item 2) [C]. Clean the contact surfaces of the filter heads. Put grease on the filter gaskets. Install the new filters.

2

1

Revised Apr. 91

–1–17–

B–07427

943 Loader Service Manual


SPARK ARRESTOR MUFFLER

A

Cleaning The Spark Arrestor Muffler The exhaust system must be tight so that exhaust fumes do not leak into the engine compartment. Higher air pressure in the engine compartment can force exhaust fumes into the operator cab. (See Operator Cab Air Seals, Page 1–6.)

1

Do not use a loader which has a defective exhaust system. Stop the engine and open the rear door. Remove the plug at the bottom of the muffler (Item 1) [A].

B–07432

Engage the parking brake. Start the engine. Wear safety goggles. Hold a piece of wood over the outlet of the muffler for about 10 seconds. Stop the engine. Install and tighten the plug. Close the rear door. Stop engine and allow the muffler to cool before cleaning the spark chamber. Wear safety goggles. Failure to obey can cause serious injury.

Cleaning Exhaust Purifier For hard carbon deposits, use the following procedure:

W–2011–1285

1. Dry–brush the inlet face of the catalyst.

When an engine is running in an enclosed area, fresh air must be added to avoid concentration of exhaust fumes. If the engine is stationary, vent the exhaust outside. Exhaust fumes contain odorless, invisible gases which can kill without warning.

2. Use air pressure through outlet face of catalyst. 3. Repeat step 1 & 2 until inlet face of catalyst is clean. 4. Completely soak the catalyst in kerosene or any carbon solvent for one hour.

W–2050–1285

5. Use solvent/air pressure through outlet face of catalyst for about 10 minutes. 6. Use air pressure through outlet face. 7. Repeat step 5 & 6 until purifier is as clean as possible. 8. Use high pressure water to wash through the outlet face of purifier. Use air pressure to dry. Maximum pressure 50 PSI (345 kPa).

This loader is factory equipped with a U.S.D.A. Forestry Service approved spark arrestor muffler. It is necessary to do maintenance on this spark arrestor muffler to keep it in working condition. The spark arrestor muffler must be serviced by dumping the spark chamber every 100 hours of operation.

NOTE: Make sure to thoroughly dry after cleaning before using, because any solvent left inside will damage the purifier. 9. Install the purifier so that the exhaust gas flows in the same direction as before cleaning.

If this machine is operated on flammable forest, brush or grass covered land, it must be equipped with a spark arrestor attached to the exhaust system and maintained in working order. Failure to do so will be in violation of California State Law, Section 4442 PRC. Make reference to local laws and regulations for spark arrestor requirements. I–2022–0595

Revised Apr. 91

–1–18–

943 Loader Service Manual


FINAL DRIVE CHAINCASE

A

Checking And Adding Chaincase Oil The loader must be on a level surface. Remove the plug (Item 1) [A] at the front of the chaincase housing.

1

The oil is at the correct level when the oil can be reached with a finger through the check plug hole. Add oil to the check plug hole as needed until the oil level is correct. Install and tighten the plug. TIRE INSPECTION AND ROTATION

B–07434

Procedure Check the tires regularly for wear, damage and correct pressure. (See Section 8 for correct tire pressure.) Rear tires usually wear faster than the front tires. To keep the tire wear even, move the rear tires to the front and the front tires to the rear [B]. Tires must be the same size and pressure for best handling of the loader. As tires become worn, match tires of equal wear and put them on the same side of the loader; two tires of equal wear on the right side and two tires of equal wear on the left side. Tire Pressure Adjust the tire pressure for work conditions before operating the loader. 70 PSI – Maximum tire pressure. Gives the best control and stability of the loader. 55 PSI – Recommended for maximum tire life. 45 PSI – Recommended for maximum flotation. Recommended tire pressure must be maintained to avoid excessive tire wear and loss of stability and handling. Tire pressure may be inflated above or below operating pressure for shipping. Check for correct pressure before operating the loader. When installing a tire on a rim, use only tires of correct size, check rim and tire bead for damage and avoid excess pressure which can rupture the tire and cause serious personal injury. During inflation put the tire in a safety cage and check the tire pressure frequently to avoid over–inflation.

B

Do not inflate tires above specified pressure. Failure to use correct tire mounting procedure can cause an explosion which can result in injury or death. W–2078–1285

C–01965

Revised Nov. 87

–1–19–

943 Loader Service Manual


TIRE INSPECTION AND ROTATION (Cont’d)

A

Wheel Nuts

Chaincase

See the SERVICE SCHEDULE Page 1–1 for the correct service interval to check the wheel nuts. The correct torque is 320–350 ft.–lbs. (434–475 Nm) torque. LOADER LUBRICATION Lubricating The Loader Lubricate the Bobcat loader as specified in the SERVICE SCHEDULE Page 1–1 for the best performance. Lubricate all the grease fittings [A].

Coolant

Hydraulic Grease Transmission Reservoir Oil filter Grease

Always use a good quality lithium–based multi–purpose grease when lubricating the loader. Apply the lubricant until extra grease shows.

6568909

B

Lubricate the seat rails (Item 1) [B] with oil for easy adjustment of the seat.

1 B–03925

Lubricate the mounting and pivot assemblies of the seat bar [C].

C

B–07387

Revised Nov. 87

–1–20–

943 Loader Service Manual


LOADER LUBRICATION (Cont’d)

A

Raise the operator cab. (See Page 1–5.) Add oil as needed to the two holes in the steering control shaft [A].

B–07480

B

Add grease to the Bob–Tach wedges at the grease fittings (Item 1) [B].

1 B–09012 B–07490

PIVOT PINS

C

Checking Pivot Pin Retainer Bolts The pivot pins, such as lift arms, Bob–Tach and cylinders have large pins that are held in position with retainer plates and bolt (Item 1) [C].

1

Check that the bolts are tightened to 20 ft.–lbs. (27 Nm) torque. Do not over–tighten.

B–11954

Added Nov. 87

–1–21–

943 Loader Service Manual


STEERING CONTROL LIMITER

A

943ServiceManual#6570008–PreventiveMaintenanceSectionPart2Of2

Lubricating The Steering Control Limiter Add grease to the steering control limiter every 50 hours of loader operation [A] & [B].

1 (S/N 11999 & Below)

B–09250

B

1

(S/N 12001 & Above)

B–12019

REMOTE START SWITCH Procedure The tool listed will be needed to do the following procedure:

C

MEL1241 – Remote Start Switch The remote start switch is required when the operator cab is in the raised position for service and the serviceman needs to start the engine. The wire harness connectors must be separated where the chassis and engine wiring harness are connected. The remote start switch is connected to the engine wiring harness connector [C]. This remote start switch is required for adjusting the steering linkage, checking charge pressure or making hydraulic/hydrostatic system checks. B–08105

Added Nov. 87

–1–22–

943 Loader Service Manual


HYDRAULIC SYSTEM Page Number BUCKET POSITION VALVE (S/N 11999 & Below) Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–47 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–47

HYDRAULIC SYSTEM

BUCKET POSITION VALVE (S/N 12001 & Above) Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–58 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–57 CHARGE PUMP Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–26 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–26 FAN MOTOR (S/N 11999 & Below) Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–44 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–46 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–43 FAN MOTOR (S/N 12001 & Above) Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–64 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–60 FAN PORT BLOCK (S/N 11999 & Below) Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–40 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–38 HYDRAULIC CONTROL VALVE Anti–Cavitation Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front Auxiliary Detent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lift Section Detent And Spool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Port Relief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Restrictor Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tilt & Rear Auxiliary Centering Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Spool Linkage End O–ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2–24 2–16 2–21 2–19 2–25 2–15 2–25 2–23 2–18

HYDRAULIC CYLINDER REPAIR Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–10 Base End And Rod Ends Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–13 Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–8 HYDRAULIC FILTER Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–51 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–50 HYDRAULIC PUMP Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–32 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–37 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–32

Continued On Next Page –2––1–

943 Loader Service Manual


HYDRAULIC SYSTEM Page Number HYDRAULIC RESERVOIR Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–49 Removing Fluid From Hydraulic Reservoir . . . . . . . . . . . . . . . . . . . . . . . 2–49 HYDRAULIC SYSTEM INFORMATION Flare Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2 O–ring Face Seal Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2 Straight Thread O–ring Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2 Tubelines and Hoses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2 JUNCTION PORT BLOCK Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–14 LIFT CYLINDER Checking The Lift Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–3 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–3 PRE–CHARGE PORT BLOCK (S/N 11999 & Below) Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–31 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–30 PORT BLOCK (S/N 12001 & Above) Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–54 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–52 QUICK COUPLERS (Bruning) Disassembly And Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–14a TILT CYLINDER Base End Pivot Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–7 Checking The Tilt Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–5 Removal And Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–5 TROUBLESHOOTING Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–1

Revised Dec. 88

–2–0–

943 Loader Service Manual


2 HYDRAULIC SYSTEM TROUBLESHOOTING The following troubleshooting chart will help to locate and correct problems which are most common. Many of the recommended procedures must be done by authorized Bobcat Service Personnel only.

PROBLEM

CAUSE

The hydraulic system will not operate.

1, 2, 3, 4, 6

Slow hydraulic system action.

1, 3, 5, 6, 7, 8, 9

Hydraulic action is not smooth.

1, 3, 7, 8

Lift arms go up slowly at full engine RPM.

1, 3, 5, 6, 7, 8, 9, 11, 12

The lift arms or Bob–Tach will move with the pedal in neutral position.

5, 11

The lift arms come down with the pedal in the neutral position.

5, 12, 13, 14, 15

The bucket does not self–level.

16, 17, 18

The bucket will partially self–level.

16, 17

The bucket has no power to roll forward.

18

The bucket does not roll back.

17 KEY TO CORRECT THE CAUSE

1.

The fluid level is not correct.

2.

The pedal linkage is disconnected.

3.

The hydraulic pump has a defect.

4.

Pressure compensator valve has a defect.

5.

The pedal linkage is not adjusted correctly.

6.

Drive belt is loose or broken.

7.

Check right and left hand auxiliary levers for neutral position.

8.

Suction leak in the hydraulic system.

9.

Fluid is cold.

10.

Using the loader for more than its rated capacity.

11.

Spool in the valve section is not returning to neutral, centering spring is broken.

12.

Internal leak at the lift cylinder(s).

13.

External leak at the lift cylinder(s).

14.

Port relief seal is leaking.

15.

Load check has a defect in the valve section.

16.

Check the flow divider in the bucket position valve.

17.

Check the unloading spool in the bucket position valve.

18.

Check the relief valve in the bucket position valve.

Revised Nov. 85

–2–1–

943 Loader Service Manual


HYDRAULIC SYSTEM INFORMATION

A

Mark a Line on Nut Flats of both Nuts

Tighten to Correct Amount from Chart

When repairing hydrostatic and hydraulic systems, clean the work area before disassembly and keep all parts clean. Always use caps and plugs on hoses, tubelines and ports to keep dirt out. Dirt can quickly damage the system. I–2003–0888

A–01897

Flare Connections

B

Use the following procedure to tighten the flare fitting:

Tube Size

Wrench Size

Tighten the nut until it makes contact with the seat. Make a mark across the Flats of both the male and female parts of the connection [A]. Use the chart to find the correct tightness needed [B]. If the fitting leaks after tightening, disconnect it and inspect the seat area for damage.

O–ring Face Seal Connection

Rotate No.

Outside Dia. . Thread Size

of Hex Flats

5/8”

5/16”

1/2” – 20

2–1/2

11/16”

3/8”

9/16” – 18

2

7/8”

1/2”

3/4” –16

2

1”

5/8”

7/8” –14

1–1/2 – 2

1–1/4”

3/4”

1–1/16” –12

1

1–3/8”

1”

1–5/16” –12

3/4 – 1

2”

1–1/4”

1–5/8” –12

3/4 – 1

2–1/4”

1–1/2”

1–7/8” –12

1/2 – 3/4

C

Tube or hose assembly installation is faster and more reliable [C]. Tube assemblies slide together. There is no need to push or pry into position. When the fitting is tightened, you can feel when the fitting is tight to eliminate leakage caused by under or over torqued fittings. Use Vaseline petroleum jelly to hold the O–ring in position until the fittings are assembled. Straight Thread O–ring Fitting When installing this fitting, the O–ring must be first lubricated. Loosen the jam nut, install the fitting into place, then tighten the jam nut. Tighten the jam nut until it and the washer are tight against the surface [D].

B–07575

D

Tubelines And Hoses

Nut

Make replacement of tubelines which are bent or have become flat. There will be a restriction of fluid flow, which will give a slow hydraulic action and cause heat.

Nut

Washer O–ring

Washer O–ring

Make replacement of hoses which show signs of wear, damage or weather cracked rubber. When installing tubelines or hoses, make sure you use two wrenches when loosening and tighten them.

A–01852

–2–2–

943 Loader Service Manual


LIFT CYLINDER

A

Checking The Lift Cylinder(s) NOTE: The maximum cylinder drift allowed is 1.300 inches (33 mm) in 10 minutes with bucket, measured at the lift cylinder rod. Lower the lift arms. Stop the engine. Activate the lift pedal to release hydraulic pressure. The lift cylinder has to be moved forward to disconnect the hose at the base end of the cylinder. See procedure below for Removal And Installation of the Lift Cylinder. Disconnect the hose which goes to the base end of the cylinder [A].

B–07629

B

Put a plug in the hose [B].

Diesel fuel or hydraulic fluid under pressure can penetrate skin or eyes, causing serious injury or death. Fluid leaks under pressure may not be visible. Use a piece of cardboard or wood to find leaks. Do not use your bare hand. Wear safety goggles. If fluid enters skin or eyes, get immediate medical attention from a physician familiar with this injury.

B–07630

W–2072–0496

C Start the engine. Push the top of the lift pedal forward. If there is fluid leakage from the open port, remove the lift cylinder for repair. Repeat this procedure to check the other lift cylinder. Removal And Installation Lower the lift arms. Stop the engine. Activate the lift pedal to release hydraulic pressure. B–07631

Put the lift pedal in the detent float position. Put a jack under the Bob–Tach and raise the lift arms. Install a jackstand [C].

D

Remove the pin retainers [D] at the rod end and base end pins of the lift cylinder. Installation: Tighten bolt to 190–240 in.–lbs. (21–27 Nm) torque. Remove the base end pivot pin and thrust washers.

B–07571

Revised Mar. 87

–2–3–

943 Loader Service Manual


LIFT CYLINDER (Cont’d)

A

Use a puller and remove the rod end and base end pins from the lift cylinder [A]. Pull the lift cylinder forward. Mark the hoses for correct installation.

B–07572

B

Disconnect both hoses [B]. Put plugs in the hose ends. Remove the lift cylinder from the loader.

B–07629

C

Installation When the rod end and base end pins are installed, make sure to align the retainer plate as the pin is installed [C].

B–07574

Revised Nov. 85

–2–4–

943 Loader Service Manual


TILT CYLINDER

A

Checking The Tilt Cylinder(s) Remove any attachment from the Bob–Tach. Roll the Bob–Tach fully back. Stop the engine. Activate the tilt pedal to release the hydraulic pressure. Put a chain around the Bob–Tach frame and the lift arms to prevent the Bob–Tach from going forward when the hoses are disconnected [A].

B–07827

B

Disconnect the hose which goes to the base end of the tilt cylinder [B].

B–07632

Put plug in the end of the hose [C].

C

Diesel fuel or hydraulic fluid under pressure can penetrate skin or eyes, causing serious injury or death. Fluid leaks under pressure may not be visible. Use a piece of cardboard or wood to find leaks. Do not use your bare hand. Wear safety goggles. If fluid enters skin or eyes, get immediate medical attention from a physician familiar with this injury.

B–07633

W–2072–0496

D

Start the engine. Push the bottom of the tilt pedal. If there is fluid leakage from the open port, remove the tilt cylinder for repair. Repeat this procedure to check the other tilt cylinder. Removal And Installation Put the Bob–Tach on the floor. Stop the engine. Activate the tilt pedal to release the hydraulic pressure. Remove the snap ring at the base end [D].

B–07634

Revised Mar. 87

–2–5–

943 Loader Service Manual


TILT CYLINDER (Cont’d)

A

Removal And Installation (Cont’d) Remove the washer from the pivot pin [A].

B–07635

B

Remove the snap ring and washer at the rod end of the tilt cylinder [B].

B–07636

C

Mark the hoses for correct installation. Disconnect both hoses at the tilt cylinder [C]. Put plugs in the ends of the hoses.

B–07632

Remove the tilt cylinder by sliding off the pivot pins [D].

D

B–08094

–2–6–

943 Loader Service Manual


TILT CYLINDER (Cont’d)

A

Tilt Cylinder Base End Pivot Pin Remove the bolt at the pivot pin [A]. Remove the washer. Installation: When installing the bolt, tighten to 220–245 ft.–lbs. (298–332 Nm) torque.

B–07637

B

Install the bolt (without washers) into the pivot pin. Hit the bolt with a hammer to remove the pin from the tapered seat [B].

B–07638

C

Remove the bolt and remove the pin from the lift arms [C].

B–07639

–2–7–

943 Loader Service Manual


HYDRAULIC CYLINDER REPAIR

A

Disassembly NOTE: The following procedure can be used for both the lift and tilt cylinders. The tools listed will be for either the lift or tilt cylinders. The tools listed will be needed to do the following procedure: MEL1075 – Gland Nut Wrench Put the base end of the cylinder in a drain pan. Move the rod in and out to remove the fluid from the cylinder barrel.

B–07640

Put the base end of the cylinder in a vise. Remove the end cap from the cylinder using the special tool [A].

B Remove the rod with the end cap and piston from the cylinder barrel. The tilt cylinder is a cushion type cylinder and has a tapered piston [B].

B–07641

The lift cylinder has a long sleeve on the rod [C].

C

B–07642

D

Put the rod end of the shaft in the vise and remove the nut [D].

B–03670

Revised Nov. 85

–2–8–

943 Loader Service Manual


HYDRAULIC CYLINDER REPAIR (Cont’d)

A

Disassembly (Cont’d) Remove the piston from the rod [A].

B–03683

B

Remove the end cap from the rod [B].

B–03685

C

Remove the O–ring and back–up washer from the end cap [C].

B–04678

Remove the wiper seal from the end cap [D].

D

B–04672

–2–9–

943 Loader Service Manual


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Bobcat 943 skid steer loader service repair manual  
Bobcat 943 skid steer loader service repair manual  
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