

The Komatsu Bulldozer D31PX-21 is a robust and versatile piece of heavy machinery designed for efficient earthmoving and construction tasks. Known for its reliability and performance, this bulldozer is ideal for various applications, ensuring optimal productivity on job sites.
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Tensioning Guide
Belt-diagram
C-120 pulleys
+ 13 more
Pre-built workflows to keep your asset running smoothly.
Daily Electrical System Inspection
Replace Roller and Pulley
Install Engine B-120
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Integrate maintenance plans directly into your work orders.
Motion Industries
Applied Industrial Technologies
Electrical Brothers
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Drive Motor
B2 Rollers
Tensioning System
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Komatsu Bulldozer D31PX-21
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500 Hourly Bulldozer Maintenance
Warning: Engine is at high temperature immediately after the machine has been operated. Wait for engine to cool down before replacing the filter.
Do not bring fire or sparks near the fuel.
Prepare a filter wrench and a container to catch the fuel.
Set the container to catch the fuel under the filter cartridge.
Using a filter wrench, turn filter cartridge (1) counterclockwise to remove it.
Clean the filter holder, fill a new filter cartridge with clean fuel, coat the packing surface with engine oil, then install it to the filter holder.
When installing, tighten until the packing surface contacts the seal surface of the filter holder, then tighten it up 1/2 to 3/4 of a turn.
After completing the replacement of filter cartridge (1), bleed the air.
Bleed the air as follows.
2000 Hourly Bulldozer Maintenance
CHANGE OIL IN HYDRAULIC TANK, REPLACE OIL FILTER CARTRIDGE AND CLEAN SUCTION STRAINER
WARNING
• The parts and oil are at high temperature after the engine is stopped, and may cause burns. Wait for the temperature to go down before starting the work.
• When removing the oil filler cap, turn it slowly to release the internal pressure, then remove it.
• Refill capacity: 44 liters
1. Lower the blade to the ground securely, stop the engine and slowly turn the cap of oil filler (F) to release the internal pressure. Then, remove the cap.
2. Remove the cover (1) at the bottom of the hydraulic tank.
3. Place a container to receive drained oil on the track under the drain hole.
4. Loosen drain valve (2) at lower side of hydraulic tank to drain the oil, then tighten valve (2) again.
4000 Hourly Bulldozer Maintenance
Water Pump Check
No play in the pulley?
No leakage of oil or water?
No clogging of the drain hole?
If any abnormality is found, please contact your Komatsu distributor for repairs or replacement.
Sign off on the water pump check
50 Hourly Bulldozer Maintenance
Warning: Carry out this check before operating the machine.
Prepare a container to catch the fuel that is drained.
Open drain valve (1) at the bottom inside the inspection cover on the left side at the rear of the machine and drain the water and sediment accumulated at the bottom together with fuel.
Warning: When doing this, be careful not to get fuel on yourself.
After clear fuel comes out, close drain valve (1).
When Required Bulldozer Maintenance
CHECK, CLEAN AND REPLACE AIR CLEANER ELEMENT
WARNING
q If inspection, cleaning, or maintenance is carried out with the engine running, dirt will get into the engine and damage it. Always stop the engine before carrying out these operations.
q When using compressed air, there is danger that dirt may be blown around and cause serious injury.
Always use safety glasses, dust mask, and other protective equipment.
CHECKING
1. Open engine side cover on the left side of machine.
2. If the yellow piston at the display portion of dust indicator (1) becomes red (7.5 kPa), clean the element.
NOTICE
Access the parts list for your equipment in MaintainX.
D31Px Power Angle Power Tilt Dozer (Narrow Blade) (Nut)
02290-11016
D31Px Power Angle Power Tilt Dozer (Narrow Blade) End Bit (Left And Right)
112-946-1510
D31Px Power Angle Power Tilt Dozer (Narrow Blade) Cutting Edge 16.5kg
12F-70-31261
Hst Charge Fllter Cartridge
714-07-28712
D31Px Power Angle Power Tilt Dozer (Wide Blade) (Nut)
02290-11016
D31Px Power Angle Power Tilt Dozer (Narrow Blade) (Nut)
02290-11016
D31Px Power Angle Power Tilt Dozer (Narrow Blade) End Bit (Left And Right)
112-946-1510
D31Px Power Angle Power Tilt Dozer (Narrow Blade) Cutting Edge 16.5kg
12F-70-31261
Hst Charge Fllter Cartridge
714-07-28712
D31Px Power Angle Power Tilt Dozer (Wide Blade) (Nut)
02290-11016
D31Px Power Angle Power Tilt Dozer (Narrow Blade) (Nut)
02290-11016
D31Px Power Angle Power Tilt Dozer (Narrow Blade) End Bit (Left And Right)
112-946-1510
D31Px Power Angle Power Tilt Dozer (Narrow Blade) Cutting Edge 16.5kg
12F-70-31261
Hst Charge Fllter Cartridge
714-07-28712
D31Px Power Angle Power Tilt Dozer (Wide Blade) (Nut)
02290-11016
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