MAINTENANCE PROCEDURE MAINTENANCE
4-32
3. Thrust bucket teeth into the ground to prevent the machine
to travel, then relief hydraulic valve (4 to 5 seconds) with
forward / reverse operation of right travel lever (2). Repeat
this operation 5 to 6 times.
q Do not carry out this forward / reverse operation on a
slippery surface (such as steel plates).
q Even if protrusion (A) of the hydraulic cushion cylinder
plunger (3) is within the specified value, HIC circuit
charge pressure may be low, so carry out Step 3 cor-
rectly.
4. Check that protrusion (A) of hydraulic cushion cylinder
plunger (3) is within the specified value on both the left and
right.
5. If protrusion (A) is not within the specified value, carry out
Step 3 again to obtain the correct value for dimension (A).
If protrusion cannot be within the specified value, there is
possibly too much grease in grease cylinder (4). In this
case, release some of the grease. For details of the proce-
dure, see “Adjust Grease Cylinder (4-33)“.
q Specified value : 135 ± 5 mm
If the end of hydraulic cushion cylinder plunger (3) is located
around center of inspection hole of crawler frame, the protru-
sion is almost within the specified value.
6. Check that drain valve (1) is fully closed.
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