

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
+ 29 more
Integrate maintenance plans directly into your work orders.
Motion Industries
Applied Industrial Technologies
Electrical Brothers
+ 5 more
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Drive Motor
B2 Rollers
Tensioning System
+ 40 more

Komatsu Komatsu Bulldozer D31PX-21 D31PX-21
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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.
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
1000 Hourly Bulldozer Maintenance
CHANGE OIL IN FINAL DRIVE CASE
WARNING: The oil is at high temperature immediately after the machine has been operated. Wait for the oil to cool down before starting the operation. If there is still pressure remaining inside the case, the oil or plug may fly out. Loosen the plug slowly to release the pressure.
Set the TOP mark at the top, with the UP mark and plug (P) perpendicular to the ground surface.
Set a container under plug (P) to catch the oil.
Remove plugs (P) and (F) with the handle and drain the oil.
Check the O-rings in the plugs for damage. If necessary, replace with new ones.
Tighten plug (P).
Add oil through the hole of plug (F).
When oil begins to overflow from the plug (F) hole, install plug (F).
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).
250 Hourly Bulldozer Maintenance
LUBRICATING
NOTICE
If dirt or sand is found sticking due to work in the soft ground, carry out greasing every 10 hours of operation.
1. Lower the blde to the ground, then stop the engine.
2. Using a grease pump, pump in grease through the grease fittings shown by arrows.
3. After greasing, wipe off any old grease that was pushed out.
q D31EX,PX , D37EX,PX
(1) Lift cylinder bottom pin (2 places)
(2) Lift cylinder head pin (2 places)
Access the parts list for your equipment in MaintainX.
D31Px Power Angle Power Tilt Dozer (Wide Blade) End Bit (Left And Right)
11G-71-31170
Recirc Filter
14X-911-7741
Hst Charge Fllter Cartridge
714-07-28712
D31Px Power Angle Power Tilt Dozer (Narrow Blade) End Bit (Left And Right)
112-946-1510
Fresh Filter
14X-911-7750
D31Px Power Angle Power Tilt Dozer (Wide Blade) End Bit (Left And Right)
11G-71-31170
Recirc Filter
14X-911-7741
Hst Charge Fllter Cartridge
714-07-28712
D31Px Power Angle Power Tilt Dozer (Narrow Blade) End Bit (Left And Right)
112-946-1510
Fresh Filter
14X-911-7750
D31Px Power Angle Power Tilt Dozer (Wide Blade) End Bit (Left And Right)
11G-71-31170
Recirc Filter
14X-911-7741
Hst Charge Fllter Cartridge
714-07-28712
D31Px Power Angle Power Tilt Dozer (Narrow Blade) End Bit (Left And Right)
112-946-1510
Fresh Filter
14X-911-7750
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