Komatsu D31EX-21, Operation & Maintenance Manual, Page: 229 / 256

MAINTENANCE
SERVICE PROCEDURE
4-49
5. Open the engine side cover at the right side of the
machine, then remove bottom cover (2).
6. Using a filter wrench, turn filter cartridge (3) counterclock-
wise to remove it.
To prevent getting oil on yourself, do not carry out this
operation from immediately under the cartridge.
7. Clean the filter holder, fill the new filter cartridge with clean
engine oil, coat the thread and packing surface of the new
filter cartridge with clean engine oil (or coat it thinly with
grease), then install it to the filter holder.
8. When installing the filter cartridge, bring the packing surface into contact with the filter holder, then tighten a
further 3/4 to1 turn.
9. After replacing the filter cartridge, add oil through oil filler
(F) until the oil level is between the H and L marks on the
dipstick (G).
10. Run the engine at idling for a short time, then stop the
engine, and check that the oil level is between the H and L
marks on the dipstick. For details, see “CHECK OIL LEVEL
IN ENGINE OIL PAN, ADD OIL (3-66)“.
REPLACE CORROSION RESISTOR CARTRIDGE 4
(If equipped)
1. Open the engine side cover on the left side of the chassis.
2. Screw in 2 valves (1) at the top of the corrosion resistor.
3. Using a filter wrench, turn cartridge (2) to the left to remove
it.
4. Apply engine oil to the sealing surface of a new cartridge,
then install it to the filter holder.
5. When installing, screw in cartridge until seal comes in contact with sealing surface, then tighten approx. 2/3
turn.
6. Open valves (1) (2 places).
Use Komatsu genuine cartridge.