MAINTENANCE PROCEDURE MAINTENANCE

● Sub-tank front engine

● Sub-tank for rear engine

Check And Tighten Track Shoe Bolts

If the machine is used with track shoe bolts (1) loose, they will break, so tighten any loose bolts immediately.

Method for tightening

1.First tighten to a tightening torque of 686 ± 69 N•m (70 ± 7 kgf•m) then check that the nut and shoe are in close contact with the link contact surface.

2.After checking, tighten a further 150° ± 10°.

Order for tightening

Tighten the bolts in the order shown in the diagram on the right. After tightening, check that the nut and shoe are in close contact with the link mating surface.

Check And Adjust Track Tension Warning

For details of starting the engine and operating the work equipment, see “BEFORE STARTING ENGINE (PAGE 3-103)”, “STARTING ENGINE (PAGE 3-124)”, “AFTER STARTING ENGINE (PAGE 3-129)”, and “WORK EQUIPMENT CONTROLS AND OPERATIONS (PAGE 3-147)” in the OPERATION section.

The wear of the pins and bushings on the undercarriage will vary with the working conditions and type of soil, so inspect the track tension frequently in order to maintain the standard tension. Stop the machine on firm, horizontal ground when carrying out the inspection and maintenance.

Checking

1.Run the engine at low idling, move the machine forward a distance equal to the length of track on ground, then stop the machine.

2.Choose wooden block (3) that will reach from 2nd carrier roller (1) to 3rd carrier roller (2), then replace it on top of the track.

3.Measure the maximum deflection between the top surface of the track and the bottom surface of the wooden block.

● Standard deflection Deflection “a” should be 10 to 30 mm.

Adjusting

If the track tension is not at the standard value, adjust it in the following manner.

Adjusting hydraulic cushion (HIC) cylinder

1.Check that stop valve (2) is completely closed.

2.Open stop valve (1).

3.Start engine and run at a medium speed.

4.Operate the right control lever to the FORWARD position intermittently (2 – 3 seconds) 3 – 4 times to relieve the travel motor.

NOTICE

● Do not carry out this operation on a slippery road surface (steel plate, etc.).

● Even when protrusion amount (A) of the hydraulic cushion is within the standard value, the HIC charge pressure may be low, so always carry out the above operation exactly.

5.Check that the protrusion (A) of the plunger of the hydraulic cushion cylinder is 135 ± 5 mm on both the left and right.

6.Close stop valve (1) completely.

Adjust grease cylinder

Do this after adjusting the hydraulic cushion cylinder.

Warning

Do not loosen fitting (1) more than one turn. If it is loosened more than one turn, there is danger that fitting (1) may fly out under the high internal pressure of the grease. When doing this, loosen only fitting (1). Do not loosen any other part. Do not put your face in the direction of installation of fitting (1). When the procedure given here is used but the track does not become loose, contact your Komatsu distributor for repairs.

Notice

Before pumping in grease, check that the protrusion (A) of the plunger of the hydraulic cushion cylinder is 135 ± 5 mm on both the left and right. Check again after pumping in grease. If the protrusion is not within this range, loosen grease fitting (1) one turn and let grease out to adjust. If the protrusion cannot be adjusted to 135 ± 5 mm, the hydraulic cushion must be adjusted, so please contact your Komatsu distributor for adjustment.

Caution

If the track tension is adjusted only by using grease and not by hydraulic pressure, excessive load may be brought to bear on the undercarriage and this may cause damage.

When increasing tension prepare a grease gun.

1.Pump in grease through grease fitting (1) with a grease gun.

2.To check that the correct tension has been achieved, move the machine backwards and forwards.

3.Check the tension again, and if it is not correct, adjust it again.

4.Continue to pump in grease until (B) becomes 35 to 190 mm. If the tension is still loose, the pin and bushing are excessively worn, so they must be either turned or replaced. Please contact your Komatsu distributor.

When loosening tension

Warning

It is extremely dangerous to release the grease by any method except the procedure given below.

If the track tension is not relieved by this procedure, please contact your Komatsu distributor for repairs.

1.Loosen plug (1) gradually to release the grease.

2.Turn plug (1) a maximum of one turn.

3.If the grease does not come out smoothly, move the machine forwards and backwards a short distance.

4.Tighten plug (1).

5.To check that the correct tension has been achieved, move the machine backwards and forwards.

6.Check the track tension again, and if the tension is not correct, adjust it again.

Check Electrical Intake Air Heater

Before the start of the cold season (once a year), contact your Komatsu distributor to have the electrical intake air heater repaired or checked for dirt or disconnections. Remove the electrical intake air heater from the engine intake manifold and check that there is no disconnection or dirt.

When inspecting or installing the electrical intake air heater, replace the gasket with a new part.

REPLACE BUCKET TEETH (VERTICAL PIN TYPE)

● Replace the bucket tooth before it wears down to the adapter.

● When replacing the bucket teeth, do not replace only both sides with new parts. If both sides only are replaced with new parts, the bucket will easily deform.

● WARNING

● It is dangerous if the work equipment moves by mistake when the teeth are being replaced. Set the work equipment in a stable condition, then stop the engine and apply the locks securely to the levers.

● If the locking pin is knocked out with excessive force, there is a hazard that the pin may fly out. Check that there is no one in the surrounding area.

● Pieces will often fly during the replacement operation, so always wear safety glasses, gloves, and other protective equipment.

1.To make it possible to knock out the pin of tooth (1), set the bottom surface of the bucket on a block, check that the work equipment is in a stable condition, then set the safety lock lever to the LOCK position. Set so that the bottom face of the bucket is horizontal.

2.Use a hammer and drift (ESCO No. MUS2267-1) to knock out lock pin (2). (If the drift is set against rubber pin lock (3) when it is hit, the rubber pin lock may break. Set it against the back of the pin.)

3.After removing lock pin (2) and rubber pin lock (3), check them.

If lock pins and rubber pin locks with the following defects are used, the teeth may come off the bucket. Replace them with new ones.

● The lock pin is too short.

The lock pin is too short 1/3 of A Align

● The rubber of the rubber pin lock is torn, and the steel balls may come out.

The rubber is broken and the steel balls come out easily

● The steel balls are buried when they are pressed by hand.

The steel balls can be buried when pressed with finger

4.Clean the surface of adapter (4) and remove the soil with a knife.

5.Use your hand or a hammer to push rubber pin lock (3) into the hole of the adapter. When doing this, be careful that the rubber pin lock does not fly out from the adapter surface.

6.Clean the inside of teeth (1), then install it to adapter (4). If there is mud affixed to it or if there are protrusions, the teeth will not enter the adapter properly, and there will not be proper contact at the mating portion.

7.Fit teeth (1) to adapter (4), and confirm that when the pointer is pressed strongly, the rear face of the hole for the pin of the teeth (1) is at the same level as the rear face of the hole for the pin of the adapter. If the rear face of the hole for the pin of teeth (1) is protruding to the front from the rear face of the pin hole for adapter (4), do not try to knock the pin in.

There is something preventing teeth (1) from entering adapter (4) fully, so remove the obstruction. When teeth (1) enters adapter (4) fully, knock in lock pin (2).

8.Insert lock pin (2) in the hole of the teeth and hit it until its top is the same level as the surface of teeth (1).

9.After replacing a bucket tooth, always check the following.

1)After the lock pin has been knocked in completely, check that it is secured by the point and surface.

2)Lightly hit lock pin (2) in the reverse direction from which it was hit in.

3)Lightly hit the tip of the point from above and below, and hit its sides from right and left.

4)Confirm that rubber pin lock (3) and lock pin (2) are set as shown in the figure.

The life of the teeth can be lengthened and the frequency of its replacement can be reduced by turning it upside down so that it will wear evenly.

Replace the rubber pin lock and locking pin at the same time as replacing the teeth. This makes it possible to prevent the teeth from falling out.

REPLACE BUCKET TEETH (HORIZONTAL PIN TYPE)

● Replace the bucket tooth before it wears down to the adapter.

● When replacing the bucket teeth, do not replace only both sides with new parts. If both sides only are replaced with new parts, the bucket will easily deform.

Warning

● It is dangerous if the work equipment moves by mistake when the teeth are being replaced. Set the work equipment in a stable condition, then stop the engine and apply the locks securely to the levers.

● If the locking pin is knocked out with excessive force, there is a hazard that the pin may fly out. Check that there is no one in the surrounding area.

● Pieces will often fly during the replacement operation, so always wear safety glasses, gloves, and other protective equipment.

1.Set the bottom of the bucket on a block to make it possible to remove pin (1), check that the work equipment is stable, then set the safety lock lever to the LOCK position.

Set so that the bottom of the bucket is horizontal.

2.Place a bar on the pin head and strike the bar with a hammer to knock out pin (1). Remove tooth (2).

Remark

If it cannot be removed by th is method, for safety reasons, always contact your Komatsu distributor to have the replacement carried out.

3.Clean the mounting face. Fit a new tooth (2) in the adapter, push in pin (1) partially by hand, then lock it with a hammer to install the tooth to the bucket.

Adjust Bucket Clearance Warning

It is dangerous if the work equipment moves by mistake when the clearance is being adjusted.

Set the work equipment in a stable condition, then stop the engine and lock the safety lock lever (1) securely.

If there is excessive free play on the coupling section of the bucket and arm, adjust the bucket clearance in the following manner.

1.Set the work equipment to the position shown in the diagram on the right, then stop the engine and set the lock lever (1) to the LOCK position.

2.Loosen 3 bolts (2), 6 bolts (3), plate (1) and plate (5).

3.Take out shims (4) equivalent in size to free play (a).

Thickness of shim (4) is 0.5 or 1.0 mm. When free play (a) is less than a thickness of shim, do not compress the shims by tightening bolt (2).

4.Tighten 3 bolts (2) and 6 bolts (3).

(A): Bucket

(B): Seal

(C): Arm

CHECK WINDOW WASHER FLUID LEVEL, ADD FLUID

If there is air in the window washer fluid, check the level of the fluid in window washer tank (1). Add automobile window washer fluid if necessary. When adding fluid, be careful not to let any dust get in.

Mixture ratio of pure washer fluid and water

Since the ratio should be varied depending on atmospheric temperature, replenish washer fluid at the following mixture ratio, taking temperature into account.

Operation area and season

Mixture ratio

Freezing temperature

NormalPure washer fluid 1/3: water 2/3–10°C

Winter in cold regionPure washer fluid 1/2: water 1/2–20°C

Winter in extremely cold region

Pure washer fluid–30°C

Pure washer fluid comes in two types: for –10°C (for general use) and for –30°C (cold regions).

Use pure washer fluid according to operation area and season.

CHECK AND ADJUST AIR CONDITIONER (ONLY MACHINES EQUIPPED WITH AIR CONDITIONER)

CHECK LEVEL OF REFRIGERANT (GAS)

WARNING

If the refrigerant used in the cooler gets into your eyes or on your hands, it may cause loss of sight or frostbite. Do not touch the refrigerant. Never loosen any part of the refrigerant circuit. Do not bring any flame close to any point where the refrigerant gas is leaking.

If there is a lack of refrigerant (Freon 134a), the cooling performance will be poor.

When operating the cooler at high speed, there should be no bubbles in the sight glass (inspection window) mounted on the condenser unit receiver.

● No bubbles in refrigerant flow: Correct

● Bubbles in refrigerant flow (bubbles continuously pass through): Refrigerant level low

● Colorless, transparent: No refrigerant

REMARK

When there are bubbles, the refrigerant gas level is low, so contact your refrigerant dealer to have refrigerant added. If the air conditioner is run with the refr igerant gas level low, it will cause damage to the compressor.

ASuitable

BLack of refrigerant

CNo refrigerant (colorless transparent)

Check in off-season

When not being used for a long period, operate the cooler for 3 to 5 minutes once a month to supply lubricant to each component of the compressor.

Inspection and maintenance items list for cooler

Inspection and maintenance items ContentsMaintenance

Refrigerant (gas)Filling quantity

Twice a year; spring and autumn

CondenserClogging of finEvery 500 hours

CompressorFunctionEvery 4000 hours

V beltDamage and tensionEvery 250 hours

Blower motor and fanFunction (Check for abnormal sound)When required

Control mechanismFunction (Check for normal function)When required

Piping for connection

Installation condition looseness of tightening connection portions gas leakage, damage

When required

CLEANING, REMOVING DIRT FROM LINE FILTER

If there is any abnormality in the pumps or other hydraulic equipment, do as follows, and remove the dirt from inside the line filter.

After assembling the line filter again, bleed the air from the system. (For details, see “PROCEDURE FOR BLEEDING AIR FROM HYDRAULIC CIRCUIT (PAGE 4-45)”)

X: As seen from left of chassisY: As seen from rear of chassis

1.Loosen the air suction plug ((1) – (5)) corresponding to the line filter to be removed 1 – 2 turns.

● Relationship of line filter and air suction plug

Line filterApplicable plug

Line filter Aplug (4)

Line filter Bplug (1)

Line filter Cplug (3)

Line filter Dplug (2)

Line filter Eplug (5)

Line filter Fplug (5)

2.Remove 4 bolts (6), and flange (7), then temporarily insert 2 of bolts (6) into cover (8).

Temporarily insert bolts (6) on diagonally opposite sides.

3.Loosen clamp (9).

4.Remove cover (8), and clean filter (10).

● When cleaning the filter, also clean off the dirt and dust stuck to the side face of the case.

● When assembling the case again, replace O-ring (11) and backup ring (12) together.

● Tightening torque for cover:108 ± 10 N·m (11 ± 1 kg·m)

Replacement Of Fan Belt And Adjustment Of Auto Tensioner

An auto-tensioner is installed, so there is no need to adjust until the belt is replaced.

Replacement

1.After loosening locknut (1), loosen adjustment screw (2) and return the adjustment screw to the surface of bracket (3).

2.Screw an eyebolt into hole (4) (ø12 x P1.25) in the tension pulley bracket, then insert a bar of approx. 50 cm in length, and pull strongly towards you.

3.The tension of the spring is extended and the tension pulley is moved to the inside, so remove the old belt and fit a new belt. Replace the V-belts as a set of 4.

Adjustment

1.Tighten adjustment screw (2), bring the tip of the adjustment screw into contact with tension pulley lever (5), then tighten the adjustment screw a further 2 turns and hold it in position with locknut (1).

2.If a gap forms between the tip of adjustment screw (2) and tension pulley lever (5) during operation, repeat the adjustment procedure in Step 1. If the fan belt screeches, use the same procedure to adjust.

Grease Ladder

(if equipped)

Stow ladder (1) as shown in the diagram on the right, then use a grease gun to supply grease to grease fitting (2).