Rockwell Armature Speed Rear Disc Brakes; Rear Brakes; Caliper, Disc And Parking Brake - Komatsu 830E Shop Manual

ROCKWELL ARMATURE SPEED REAR DISC BRAKES

REAR BRAKES

Each rear wheel service brake assembly consists of
two discs, each with a four piston caliper and a lining
on each side of the disc. Both discs are attached by
adapters to the wheel motor armature. Also mounted
on each wheel motor is a dual piston, two lining caliper
acting on each outboard disc as a parking brake.
NOTE: Some trucks may be equipped with TWO (2)
Park Brake Calipers
adjustment for these calipers are the same as
presented here.
A constant brake-release clearance between pistons
and linings, and lining and disc, is maintained by an
automatic adjustment feature of the piston subassem-
bly. As lining wears, the position of grips on a return pin
advances to allow maximum piston force to be applied
to lining. Upon brake release, the piston is retracted by
a return spring for the amount of the predetermined
clearance.
FIGURE 6-1. PARKING BRAKE
1. Parking Brake Caliper
2. Capscrew
3. Mounting Bracket
J06020
per wheel. Service and
4. Jam Nut
5. Adjustment Bolt
6. Clamping Capscrew
Rockwell Armature Speed Rear Disc Brakes
CALIPER, DISC, AND PARKING BRAKE
Do not loosen or disconnect any hydraulic brake
line or component until engine is stopped, key
switch is "Off" and drain valves on brake accumu-
lators are opened and steering accumulator is bled
down. Turn steering wheel to be sure steering
accumulator is completely bled down.
Caliper, Disc, and Parking Brake Removal
NOTE: For electric wheels equipped with a two-piece
brake hub adapter (9 & 20, Figure 6-3), follow the
instructions below. For electric wheels equipped with a
one-piece wheel adapter (16, Figure 6-3A), refer to
page 4.
NOTE: The Park Brake caliper may be removed from
either wheelmotor without disassembly of other brake
components.
1. Securely block wheels to prevent truck move-
ment.
2. Remove rear wheel cover.
3. Open the highest bleeder valve (5, Figure 6-2)
and attach a bleeder hose to the lowest bleeder
valve (6). Open bleed valve and allow oil to drain
into a container. Disconnect and remove brake
supply tubes from service and park brake cali-
pers. Take care to prevent hydraulic oil from com-
ing in contact with commutator and brushes of
wheelmotor.
4. Disconnect brake line connected to the park
brake caliper.
5. Loosen jam nut (4, Figure 6-1) on park brake
adjustment bolt (5). Loosen clamping capscrew
(6) one turn and back out adjustment bolt (5) six
turns to release park brake linings from outer
disc.
6. Support park brake caliper and remove cap-
screws (2) securing caliper (1) to park brake
mounting bracket (3). Remove caliper from disc.
7. Remove crossover tube (4, Figure 6-2) from
upper service brake caliper. Remove crossover
tube on lower brake assembly.
8. Removal of brake caliper is easier with linings
removed. Remove retainer capscrews (1), lining
retainers (2) and linings.
J6-1