Maintenance; Inspection; Removal - Komatsu 930E-2 Shop Manual

MAINTENANCE

The parking brake system requires periodic inspection
to determine the amount of wear incurred to insure
adequate brake torque is available. The following in-
spection should be made at 500 hour intervals.

Inspection

1. Apply the parking brake, put selector switch in
NEUTRAL, place the Rest switch in the ON posi-
tion, turn the key switch OFF to shut down the
engine, and allow approximately 90 seconds for
the steering accumulators to bleed down. Confirm
the steering pressure is released by turning the
steering wheel - no movement should occur.
Block the truck wheels.
2. Open brake accumulator bleeddown valves lo-
cated on brake manifold inside the hydrauilc com-
ponents cabinet behind the cab. Allow adequate
time for the accumulators to bleed down com-
pletely.
3. Open the rear axle housing access door and
remove wing nuts retaining duct inside door. Re-
move duct tube and open access covers inside
axle housing.
4. Observe for signs of oil leakage or damage.
5. Measure amount of disc wear as follows:
a. With the parking brake applied, insert a depth
micrometer through one of the piston position
holes (18, Figure 7-2) and record the dimen-
sion.
b. Repeat step a., measuring through the other
two holes and recording the dimensions.
c. Add the three measurements and divide the
total by 3 to determine the average.
d. If the resulting average of the three measure-
ments is greater than 0.969 in. (24 mm), the
parking brake assembly must be removed and
rebuilt.
6. Repeat step 5 for the other parking brake assem-
bly.
7. After inspection is complete, close duct access
covers and reinstall duct outlet tube.
J7-2

Removal

Parking brake repairs should be performed when the
wheel motor is removed from the truck whenever pos-
sible. If repairs are necessary when the wheel motor is
installed, it will be necessary to setup a lifting device
inside the rear axle housing to support the weight of
the brake assembly when it is removed from the wheel
motor.
If repairs are made when the wheel motor is removed,
follow the appropriate procedures below. If repairs
must be accomplished with the wheel motor installed
on the truck, follow all procedures listed below.
The parking brake assembly weighs approximately
350 lbs. (159 kg). Be certain a lifting device capa-
ble of supporting the weight is used to support the
brake assembly when removed.
1. Apply the parking brake, put selector switch in
NEUTRAL, place the Rest switch in the ON posi-
tion, turn the key switch OFF to shut down the
engine, and allow approximately 90 seconds for
the steering accumulators to bleed down. Confirm
the steering pressure is released by turning the
steering wheel - no movement should occur.
Block the truck wheels.
2. Block wheels securely to prevent truck movement
during parking brake repair.
3. Open brake accumulator bleeddown valves lo-
cated on brake manifold inside the hydrauilc com-
ponents cabinet behind the cab. Allow adequate
time for the accumulators to bleed down com-
pletely.
4. Open the rear axle housing access door and
remove wing nuts retaining duct inside door. Re-
move duct tube and open access covers inside
axle housing. Remove ducts as required to setup
a lifting device for brake removal.
5. Disconnect park brake apply supply hose (7, Fig-
ure 7-1).
6. Remove capscrews and lockwashers (9). Install
guide studs in two of the mounting holes to sup-
port brake assembly when removed from wheel
motor frame.
7. Slide parking brake assembly out of wheel motor
frame and off inner gear (4). Remove from axle
housing
Parking Brake J07010 12/98