Rockwell Wheel Speed Front Disc Brakes; Brake Caliper - Komatsu 830E Shop Manual

ROCKWELL WHEEL SPEED FRONT DISC BRAKES

BRAKE CALIPER

Each front wheel speed brake assembly has three*
calipers on one disc. Each caliper has six pistons
and two linings (three apply pistons and one lining for
each side of disc). Lining should be changed when
friction material is worn to 0.125 in. (3.22 mm) thick-
ness.
*NOTE: Some trucks may be equipped with FOUR
(4) Brake Calipers per
adjustment for these calipers are the same as
presented here.
If inspection of front brake calipers and disc assem-
bly indicate repair beyond lining replacement, it is
necessary to remove calipers and disc from front
wheel hub and spindle. Refer to Figure 5-4 for maxi-
mum wear limits of front disc.
Clean brake assemblies before performing any ser-
vice. If brake has not accumulated excessive surface
dirt, preliminary cleaning can be done in the overhaul
area. However, preliminary cleaning should be done
before removal of pistons from housing.
• Cleaning may be done by brush or spray, using
a petroleum base cleaning solvent.
• Clean diesel fuel is acceptable for this
operation.
• Cleaning should be thorough enough for
preliminary inspection and disassembly.
• Subassemblies should be blown dry with
compressed air after cleaning. Dust shields
should be wiped dry with a clean cloth.
• The use of vapor degreasing or steam cleaning
is not recommended for the brake assemblies
or the component parts. Moisture will cause
parts to rust.
Be certain that all wheels are securely blocked to
prevent truck from moving.
Do not loosen or disconnect any hydraulic brake
line or component until engine is stopped, key
switch is "Off" and drain valves on brake accu-
mulators are opened and steering accumulators
are bled down. Turn steering wheel to be sure
steering accumulators are completely bled down.
J05019
wheel. Service and
Rockwell Wheel Speed Front Disc Brakes
Caliper Removal
1. Remove front tires and rims according to proce-
dure in Section "G".
2. If necessary, remove disc from front wheel hub.
Refer to Section "G", "Front Wheel Hub and
Spindle Removal".
NOTE: Mark or tag each brake caliper assembly for
reassembly at its correct location. Do not interchange
parts.
3. Open the brake bleed valves (2, Figure 5-3) at
each caliper and bleed down the caliper by dis-
connecting the two lower hoses at "T" connec-
tion (5 & 6, Figure 5-1). Drain the fluid into a
container. Do not reuse fluid.
4. Disconnect the top brake hose at "T" connec-
tion (3).
5. Disconnect and remove crossover tubes (2, 4,
& 7).
FIGURE 5-1. FRONT BRAKE ASSEMBLY
1. Brake Adapter
2. Crossover Tube
3. "T" Connection
4. Crossover Tube
5. "T" Connection
6. "T" Connection
7. Crossover Tube
8. Junction Block
J5-1