Komatsu D31EX-21, Operation & Maintenance Manual, Page: 205 / 256

MAINTENANCE
SERVICE PROCEDURE
4-25
7. After draining the water, clean the cooling system with cleaning agent.
For the cleaning method, see the instructions for the cleaning agent.
8. Close drain valve (2). Wind seal tapes onto drain plug (3), then tighten it.
9. Add coolant until it overflows from the water filler.
Decide the proportions of antifreeze and water according to the table for the mixing rate of water and anti-
freeze.
10. To remove the air in the coolant, run the engine for 5 minutes at low idling, then for another 5 minutes at high
idling. (While doing this, leave the radiator cap removed)
11. Drain the cooling water inside sub-tank (4), clean the inside
of the sub-tank, then fill again with cooling water to a point
midway between the FULL and LOW marks.
12. Stop the engine and tighten the cap. Check the coolant
level, and add water if the level is low.
CHECK TRACK SHOE TENSION, ADJUST 4
The wear of pins and bushings on the undercarriage will vary with the working conditions and types of soil. 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 (a) is
20 to 30 mm, the tension is standard.
If the track tension is not at the standard value, adjust it in the
following manner.
ADJUSTMENT
WARNING
There is danger of plug (1) flying out under the high inter-
nal pressure of the grease. Never loosen plug (1) more
than 1 turn.
Never loosen any part other than plug (1). Never put your
face in the mounting direction of plug (1).
If the track tension cannot be loosened with the procedure
given here, please contact your Komatsu distributor.
FULL
LOW