Komatsu D31EX-21, Operation & Maintenance Manual, Page: 119 / 256

OPERATION
OPERATION
3-67
CHECK, CLEAN WATER SEPARATOR
This is inside the inspection cover at the left side at the rear of
the machine.
Water separator (1) separates the water and dirt from the fuel.
If float (2) goes above water drain level (3), drain the water as
follows.
1. Loosen drain (4) and drain the accumulated water until the
float (2) reached the bottom.
2. Tighten drain plug (4).
3. If the air is sucked into fuel line when draining and water,
be sure to bleed air in the same manner as for the fuel fil-
ter. See “REPLACE FUEL FILTER CARTRIDGE (4-45)“.
If element (5) inside the water separator is clogged with
dirt, remove the dirt as follows.
4. Set handle (6) at the side of the water separator to the
CLOSE position.
5. Using the filter wrench, loosen ring (7), remove element
cup (8), then take out element (5).
REMARK
Be careful not to lose the O-ring, float, or spring. Be sure to
assemble them after washing.
6. Wash element cup (8) and element (5) in diesel oil or flushing oil.
7. Assemble element (5) in element cup (8), then fill with fuel.
8. Set element cup (8) in position, then tighten ring (7) to install it.
9. Turn handle (6) to the OPEN position.
10. After washing the water separator, bleed the air from the fuel circuit. For details of the procedure for bleeding
the air, see “REPLACE FUEL FILTER CARTRIDGE (4-45)“.