General • Inspections

Komatsu Bulldozers D65EX,PX-12 : When Required Maintenance

Use this maintenance checklist for the proactive and preventive maintenance of your bulldozer. This has been proven to lower costs by catching small service issues before they blossom into giant repair headaches.

MaintainX

11/04/2022

Komatsu Bulldozers D65EX,PX-12 : When Required Maintenance

CLEAN REQUIRED INSIDE OF COOLING SYSTEM

WARNING

Soon after the engine has been stopped, the coolant is hot and can cause personal injury
Allow the engine to cool before draining water
Never be under the machine with the engine running.
To avoid serious injury, always stop the engine before being under the machine to open the drain valve.
Never remove the radiator cap when the engine is at operating temperature. At operating temperature, the coolant is under pressure. Steam blowing up from the radiator could cause personal injury.
Allow the engine to cool until the radiator filler cap is cool enough to touch with your hand.
Remove the filler cap slowly to relieve pressure.
When removing drain plug, avoid pouring coolant on yourself.
Antifreeze is flammable, so keep it away from any flame.

Clean the inside of the cooling system, change the coolant and replace the corrosion resistor according to the table below.

Use a permanent type of antifreeze. If, for some reason, it is impossible to use permanent type antifreeze, use an antifreeze containing ethylene glycol.

Stop the machine on level ground when cleaning or changing the coolant.

When deciding the ratio of antifreeze to water, check the lowest temperature in the past, and decide from the mixing rate table given below. It is actually better to estimate a temperature about 10°C lower when deciding the mixing rate.

We recommend use of an antifreeze density gauge to control the mixing proportions.

Use city water for the cooling water. If river water, well water or other such water supply must be used, contact your Komatsu distributor.

Turn radiator cap 1 slowly to remove it.

Set a container to catch the coolant under drain valve 2 and drain plug 3. Open drain valve 2 at the bottom of the radiator and drain plug 3 on the side face of the cylinder block to drain the water.

After draining the water, close drain valve 2 and drain plug 3, and fill with city water.

Open drain valve 2 and drain plug 3, run the engine at low idling, and flush water through the system for 10 minutes. When doing this, adjust the speed of filling and draining the water so that the radiator is always full. While flushing water through the system, watch carefully that the water inlet hose does not come out of the radia- tor water filler.

After flushing, stop the engine, open drain valve 2 and drain plug 3, then close it again after all the water has drained out.

After draining the water, clean with a flushing agent. When washing, follow the instructions given with the detergent.

After flushing, open drain valve 2 and drain plug 3, completely drain all the water, then close the drain valve and drain plug, and fill with city water up to near the filler port.

When the tank is filled to near the water filler port, open drain valve 2 and drain plug 3, start the engine, run at low idling, and continue the flushing operation until clean water comes out. Adjust the amount of water flowing in and out to ensure that the radiator is always full during the flushing operation.

Add city water until the water overflows from the water filler port.

To remove the air in the cooling water, run for five minutes at low idling, then for another five minutes at high idling. (When doing this, leave the radiator cap off.)

Drain the cooling water inside sub-tank 4, clean the inside LOW of the sub-tank, then fill again with cooling water to a point midway between the FULL and LOW marks.

Stop the engine, wait for 3 minutes, add city water until the water level reaches near the water filler port, then tighten the cap.

CHECK, CLEAN AND REPLACE AIR CLEANER ELEMENT

WARNING

Never clean or replace the air cleaner element with the engine running.
When using pressure air to clean the element wear safety glasses or goggles to protect the eyes.

Checking

Whenever the red piston in dust indicator 1 appears, clean the air cleaner element.

Cleaning or replacing outer element

Loosen bolt 2, remove cover 3 and the outer element.
Clean the air cleaner body interior and the dust cup.

Direct dry compressd air (less than 7 kg/cm2) to the element from inside along its folds, then direct it from outside along its folds and again from inside.

Remove one seal from the outer element. The number of times the outer element has been cleaned can be seen by the number of removed seals.
Replace the outer element which has been cleaned 6 times repeatedly or used throughout a year. Replace the inner element at the same time.
Replace the element when the air cleaner clogged warning lamp lights up soon after installing the cleaned element even though it has not been cleaned 6 times.
Check inner element mounting nuts for looseness and, if necessary, retighten.
Replace seal washer 4 or wing nut 5 with new parts if they are broken.
Remove evacuator valve 6 and clean with compressed air. After cleaning, install it.

NOTICE

If small holes or thinner parts are found on the element when it is checked with an electric bulb after cleaning and drying, replace the element.
Do not use an element whose folds or gasket or seal are damaged.
When cleaning the element, do not hit it or beat it against something.

Set the cleaned element and cover 3.

Replacing inner element

1. First remove the cover and the outer element, and then remove the inner element.
2. To prevent dust from getting in, use a clean cloth or tape to cover the air connector (outlet side).
3. Clean the air cleaner body interior, then remove the cover installed in Step 2.
4. Fit a new inner element to the connector and tighten it with nuts. Do not clean and reinstall a inner element.
5. Install the outer element and the cover.
6. After replacing the element, return the red piston in the dust indicator to its original position.

CHECK TRACK TENSION

The wear of pins and bushings on the undercarriage will vary with the working conditions and soil properties. It is thus necessary to continually inspect the track tension so as to maintain the standard tension.

Carry out the check and adjustment under the same conditions as when operating (on jobsites where the track becomes clogged with mud, measure with the track clogged with mud).

Inspection

Stop the machine on level ground (stop with the transmission in FORWARD without applying the brake).
Then place a straight bar on the track shoes between the carrier roller and the idler as shown in the figure, and measure the clearance between the bar and the grouser at the midpoint. If the clearance is 20 - 30mm, the tension is standard.
If the track tension is not at the standard value, adjust it in the following manner.

Adjustment

When increasing tension

Pump in grease through the grease pump.
To check that the correct tension has the machine backwards and forwards.
Check the track tension again, and if the tension is not correct, adjust it again.
Continue to pump in grease until S becomes 0 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

Loosen lubricator 1 gradually to release the grease.
Turn lubricator 1 a maximum of one turn.
If the grease does not come out smoothly, move the machine backwards and forwards a short distance.
Tighten lubricator 1.
To check that the correct tension has been achieved, move the machine backwards and forwards.
Check the track tension again, and if the tension is not correct, adjust it again.

CHECK AND TIGHTEN TRACK SHOE BOLTS

If the machine is used with track shoe bolts 0 loose, they will break, so tighten any loose bolts immediately.

Method for tightening (shoe bolt)

First tighten to a tightening torque of 40 + 4 kgm, then check that the nut and shoe are in close contact with the link contact surface.
After checking, tighten a further 120° + 10°.

Method for tightening (master link connecting bolt)

First tighten to a tightening torque of 35 + 4 kgm, then check that the link contact surfaces are in close contact.
After checking, tighten a further 180°

Order for tightening

Tighten the bolts in the order shown in the diagram on the right.

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.

REVERSE AND REPLACE THE END BITS AND CUTTING EDGES

WARNING: It is dangerous if the work equipment moves by mistake when the cutting edges and end bits are being reversed or replaced. Set the work equipment m a stable condition, then stop the engine and lock the blade control lever securely with the safety lever.

Reverse or replace the end bits and cutting edges before it is worn out to the blade end.

Raise the blade to a proper height and apply a block to the frame so as to prevent fall of the blade.
Operate the safety lever to the LOCK position.

Measure the wear of the end bit and cutting edge in accordance with the wear standards given below.

If the cutting edge and the end bit on both sides are worn out, replace with new one.

If it has been worn out up to the fitting surface, repair the fitting surface and then reverse or replace.

Remove the cutting edge and the end bit and clean the mounting surface.

Reverse or replace the cutting edge and the end bit when worn out.

If bolt 1 and nut 2 are damaged, replace them with new ones at the same time.

After several hours of running, retighten the nuts.

CLEAN, CHECK RADIATOR FINS

WARNING: If compressed air, steam, or water hit your body directly, there is danger of injury. Always wear protective glasses, mask, and safety shoes.

If the radiator fins are clogged or dirty, clean and inspect them.

Remove bolts 1 (4 bolts).
Open the A side (hinge side) of the radiator mask. It opens approx. 10 mm.
Leave the B side of the radiator mask open.
Clean the radiator fins clogged with mud, dust and leaves with compressed air. Steam or water may be used instead of compressed air.

REMARK: Check the rubber hose. If the hose is found to have cracks to be hardened by ageing, replace such hose with new one. Further, loosen hose clamp should also be checked.

When closing the radiator mask, always push in the A side first, then push in the B side, align the bolt holes, and tighten bolt 1.

ADJUST IDLER CLEARANCE

Since the idlers are forced to move forward and backward by an external force guide plates 2 will be worn out.

Wear of these plates will cause the vibration of idlers from side to side or inclination of the idlers, and running off of track links from the idlers or unevenly worn idler and links may result.

Therefore, adjust the idlers according to the following procedure.

Adjustment

Move machine about 1 or 2 meters on a flat ground.
Measure the clearance A (4 locations: left, right, inside and outside) between the track frame and the guide plate.
If the clearance A exceeds 4.0 mm, loosen bolt 0, and pull out the shim to adjust the clearance at one end to 0.5 - 1.0 mm.

REMARK: Thickness of one shim is 1.0 mm.

ADJUSTING TENSION OF CENTER BRACE (POWER TILT DOZER ONLY) (POWER TILT, POWER PITCH DOZER ONLY)

When the blade assembly is removed for transportation, the tension of the center brace must be adjusted when the blade is assembled again. If the tension is not adjusted, the bushing at the blade and straight frame mount will come out, and soil will enter. This will result in damage or premature wear of the bushing.

WARNING: Except when operating the blade in Step 4, always lock the blade control lever securely with the safety lever.

Adjustment

1. Adjust with shim 2 so that the play of ball joint 1 is 0.2 - 0.5 mm.
2. Loosen bolt 3.
3. Install the blade assembly.
4. Install the blade assembly. Operate the blade control lever to float the blade.
5. Install the blade assembly. Operate the blade control lever to float the blade. Insert a bar in hole 4 in the center brace, and turn it in the direction of protrusion. When doing this, adjust so that clearance D between the track and frame is the same on the left and right sides. Rotating torque: 2.5 - 5 kgm (Blade at FLOAT) Standard distance (Q) between joints: 995 mm
Tighten bolt D. Tightening torque: 45 k 5 kgm

CLEAN AIR CONDITIONER AIR FILTER (FRESH/RECIRC FILTER) (MACHINES EQUIPPED WITH CAB)

If the air conditioner air filter is clogged or there is dirt or dust in it, clean the filter.

Open inspection cover 1, remove cover 2, then remove FRESH filter 3.
Open inspection cover 4 under the front panel, pull up RECIRC filter 5, and remove it.
Clean filters 3 and 5 with compressed air.
If there is oil stuck to the filter, or it is extremely dirty, wash it in a neutral agent.
After washing it, dry it completely before installing it again,
If the clogging of the filter cannot be removed by washing or using compressed air, replace the filter with a new part.

CHECK, ADJUST AIR CONDITIONER (MACHINES EQUIPPED WITH CAB)

CHECKING TENSION OF COMPRESSOR BELT

If the belt is loose, it will slip and the cooling effect will be reduced. From time to time, press a point midway between the drive pulley and compressor pulley with your finger (approx. 10 kg) and check that the tension is 15 - 18 mm.
When the belt is new, there will be initial elongation, so always adjust again after 2 or 3 days.

CHECK LEVEL OF REFRIGERANT (GAS)

If the level of the refrigerant (gas) is low, the cooling effect will be reduced. Run the engine at high idling, and check the flow of the refrigerant in the refrigerant circuit through the sight glass of the receiver when the cooler is running at high speed.

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 refrigerati gas level low, it will cause damage to the compressor.

GREASE DOOR HINGE (MACHINES EQUIPPED WITH CAB)

If the door makes a squeaking noise when it is opened or closed, spray lubricant in through the split in the hinge bushing.
If the bushing is worn, replace the hinge.

CHECK DOOR LOCK STRIKER (MACHINES EQUIPPED WITH CAB)

If the wear of the doors lock striker exceeds 0.5 mm, replace the striker. If it is used at it is, the play will increase and this may result in breakage of the hinge or door lock.

REPLACE DOOR DAMPER (MACHINES EQUIPPED WITH CAB)

If the depth of the door damper rubber groove is less than 2 mm, replace the damper. There are two dampers each at the top and bottom on the left and right doors.

CHECK WINDOW WASHER FLUID LEVEL, ADD FLUID (MACHINES EQUIPPED WITH CAB)

If there is air in the window washer fluid, check the level and add fluid.
Open the engine side cover on the right side, check the level of the fluid in window washer tank 1, and if it is low, add automobile window washer fluid.
When adding fluid, be careful not to let dirt or dust get in.

BLEED AIR FROM HEAD END OF RIGHT PITCH CYLINDER (POWER TILT, POWER PITCH DOZER ONLY)

Bleed the air if the work equipment has been removed or repaired.
Raise the blade and run the engine at low idling.
Operate the left and right tilt 5 - 10 times to bleed the air from the tilt circuit.
Operate the forward and rear pitch 5 - 10 times to bleed the air from the bottom end of the right cylinder.
Set the left and right cylinders at the neutral position, then carry out the following operations 5 - 10 times to bleed the air from the head end of the right pitch cylinder.

REPLACE WIPER BLADE (MACHINES EQUIPPED WITH CAB)

If the blade is damaged, it will not wipe the window clean, so replace the blade.

Method of replacement

Front, rear wiper

Remove screw 1, then remove the blade.
Install a new blade, then tighten screw 1 securely.

Door wiper

It is hooked at portion A, so move the blade in the direction of the arrow to remove it.
Install the new blade and hook it securely.

CHECK IDLER OIL LEVEL, ADD OIL

If the oil level in the idler is low, noise will be generated and there will be seizure, so check the oil level and add oil as follows.

Checking

Remove bolt 1, then remove cover 2.
Remove bolt 3, then remove guide plate 4 and shim 5. When removing shim 0 keep it in a safe place and be careful not to lose it.
Loosen plug 6 and check if oil comes out.
If oil comes out the oil level is correct.
If no oil comes out, drive the machine on to a block to tilt the machine. Then remove plug 6 and add engine oil through oil filler port F.
After adding oil, install plug 6.
Install guide plate 4 and shim 5 with bolt 3.
Install cover 2 with bolt 1.

Source: MaintainX (Community Member)

CLEAN REQUIRED INSIDE OF COOLING SYSTEM

WARNING

Soon after the engine has been stopped, the coolant is hot and can cause personal injury

Allow the engine to cool before draining water

Never be under the machine with the engine running.

To avoid serious injury, always stop the engine before being under the machine to open the drain valve.

Never remove the radiator cap when the engine is at operating temperature. At operating temperature, the coolant is under pressure. Steam blowing up from the radiator could cause personal injury.

Allow the engine to cool until the radiator filler cap is cool enough to touch with your hand.

Remove the filler cap slowly to relieve pressure.

When removing drain plug, avoid pouring coolant on yourself.

Antifreeze is flammable, so keep it away from any flame.

Clean the inside of the cooling system, change the coolant and replace the corrosion resistor according to the table below.

Use a permanent type of antifreeze. If, for some reason, it is impossible to use permanent type antifreeze, use an antifreeze containing ethylene glycol.

Stop the machine on level ground when cleaning or changing the coolant.

When deciding the ratio of antifreeze to water, check the lowest temperature in the past, and decide from the mixing rate table given below. It is actually better to estimate a temperature about 10°C lower when deciding the mixing rate.

We recommend use of an antifreeze density gauge to control the mixing proportions.

Use city water for the cooling water. If river water, well water or other such water supply must be used, contact your Komatsu distributor.

Turn radiator cap 1 slowly to remove it.

Set a container to catch the coolant under drain valve 2 and drain plug 3. Open drain valve 2 at the bottom of the radiator and drain plug 3 on the side face of the cylinder block to drain the water.

After draining the water, close drain valve 2 and drain plug 3, and fill with city water.

After flushing, stop the engine, open drain valve 2 and drain plug 3, then close it again after all the water has drained out.

After draining the water, clean with a flushing agent. When washing, follow the instructions given with the detergent.

After flushing, open drain valve 2 and drain plug 3, completely drain all the water, then close the drain valve and drain plug, and fill with city water up to near the filler port.

Add city water until the water overflows from the water filler port.

To remove the air in the cooling water, run for five minutes at low idling, then for another five minutes at high idling. (When doing this, leave the radiator cap off.)

Drain the cooling water inside sub-tank 4, clean the inside LOW of the sub-tank, then fill again with cooling water to a point midway between the FULL and LOW marks.

Stop the engine, wait for 3 minutes, add city water until the water level reaches near the water filler port, then tighten the cap.

CHECK, CLEAN AND REPLACE AIR CLEANER ELEMENT

WARNING

Never clean or replace the air cleaner element with the engine running.

When using pressure air to clean the element wear safety glasses or goggles to protect the eyes.

Checking

Whenever the red piston in dust indicator 1 appears, clean the air cleaner element.

Cleaning or replacing outer element

Loosen bolt 2, remove cover 3 and the outer element.

Clean the air cleaner body interior and the dust cup.

Direct dry compressd air (less than 7 kg/cm2) to the element from inside along its folds, then direct it from outside along its folds and again from inside.

Remove one seal from the outer element. The number of times the outer element has been cleaned can be seen by the number of removed seals.

Replace the outer element which has been cleaned 6 times repeatedly or used throughout a year. Replace the inner element at the same time.

Replace the element when the air cleaner clogged warning lamp lights up soon after installing the cleaned element even though it has not been cleaned 6 times.

Check inner element mounting nuts for looseness and, if necessary, retighten.

Replace seal washer 4 or wing nut 5 with new parts if they are broken.

Remove evacuator valve 6 and clean with compressed air. After cleaning, install it.

NOTICE

If small holes or thinner parts are found on the element when it is checked with an electric bulb after cleaning and drying, replace the element.

Do not use an element whose folds or gasket or seal are damaged.

When cleaning the element, do not hit it or beat it against something.

Set the cleaned element and cover 3.

Replacing inner element

1. First remove the cover and the outer element, and then remove the inner element.

2. To prevent dust from getting in, use a clean cloth or tape to cover the air connector (outlet side).

3. Clean the air cleaner body interior, then remove the cover installed in Step 2.

4. Fit a new inner element to the connector and tighten it with nuts. Do not clean and reinstall a inner element.

5. Install the outer element and the cover.

6. After replacing the element, return the red piston in the dust indicator to its original position.

CHECK TRACK TENSION

The wear of pins and bushings on the undercarriage will vary with the working conditions and soil properties. It is thus necessary to continually inspect the track tension so as to maintain the standard tension.

Carry out the check and adjustment under the same conditions as when operating (on jobsites where the track becomes clogged with mud, measure with the track clogged with mud).

Inspection

Stop the machine on level ground (stop with the transmission in FORWARD without applying the brake).

Then place a straight bar on the track shoes between the carrier roller and the idler as shown in the figure, and measure the clearance between the bar and the grouser at the midpoint. If the clearance is 20 - 30mm, the tension is standard.

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

Adjustment

When increasing tension

Pump in grease through the grease pump.

To check that the correct tension has the machine backwards and forwards.

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

Continue to pump in grease until S becomes 0 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

Loosen lubricator 1 gradually to release the grease.

Turn lubricator 1 a maximum of one turn.

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

Tighten lubricator 1.

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

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

CHECK AND TIGHTEN TRACK SHOE BOLTS

If the machine is used with track shoe bolts 0 loose, they will break, so tighten any loose bolts immediately.

Method for tightening (shoe bolt)

First tighten to a tightening torque of 40 + 4 kgm, then check that the nut and shoe are in close contact with the link contact surface.

After checking, tighten a further 120° + 10°.