Operation and maintenance manual

Parking Brake - Parking Brake and Mounting
Section 170-0010
2
SM 2253 10-03
the ignition is switched off.
REMOVAL
Numbers in parentheses refer to Fig. 1, unless
otherwise specified.
WARNINGS
To prevent personal injury and property
damage, be sure wheel blocks, blocking
materials and lifting equipment are properly
secured and of adequate capacity to do the job
safely.
Hydraulic fluid pressure will remain
within the braking system after engine shut
down. Operate the treadle pedal continuously
until the pressure has dissipated before
carrying out any work on the braking system or
serious injury could result.
1. Position the vehicle on a level surface, apply the
parking brake, block all road wheels and place the
steering lock bar in the 'Locked' position.
2. Raise the body and install body safety prop to
secure in partially raised position.
3. Pull out push control to release the parking brake.
4. Release spring tension on slack adjuster clevis pin
(7) by unscrewing tensioning bolt on slack adjuster (3)
until clevis pin (7) feels loose. Remove cotter pin (8)
and clevis pin (7) from actuator (9).
5. Switch off the engine and place the battery master
switch in the 'Off' position.
6. Disconnect and plug hydraulic line from actuator (9).
Cap actuator (9) to prevent ingress of dirt.
7. Remove nuts (10) and washers (11) securing
actuator (9) to cap assembly (13). Remove actuator (9)
from cap assembly (13).
8. Support calliper head assembly (2) and remove bolts
(4), washers (5) and nuts (6) securing bracket
assembly (1) to mounting bracket on the frame.
9. Remove bracket assembly (1) and calliper head
assembly (2) from the vehicle.
10. Slide calliper head assembly (2) from bracket
assembly (1) and set aside for disassembly.
Note: Service of actuator (9) is covered in Section
170-0030, ACTUATOR.
DISASSEMBLY
Numbers in parentheses refer to Fig. 2.
1. Remove calliper head assembly as described under
removal.
2. Remove snap ring (14) from power screw shaft (19).
3. Slide slack adjuster (15) from power screw shaft (19).
4. Remove and discard washer (16), wave spring
washer (17) and packing (18) from power screw
shaft (19).
5. Remove bolts (2) and washers (3) securing cap
assembly (22) to calliper (7).
6. Remove as a unit, power screw shaft (19),
piston (6) and cap assembly (20 through 23) from
calliper (7).
7. Slide power screw shaft (19) and piston (6) from cap
assembly (22).
8. Unscrew piston (6) from power screw shaft (19).
9. Remove and discard thrust bearing (20) from power
screw shaft (19) and gasket (21) from cap
assembly (22).
10. Remove and discard piston seal (5) from calliper (7).
INSPECTION
Numbers in parentheses refer to Fig. 2.
1. Thoroughly clean all parts. Inspect journal bearing
(23) in cap assembly (22) for wear. Journal bearing (23)
ID should not exceed 38.35 mm (1.51 in). Replace if
necessary.
2. Replace cap assembly (22) if excessively worn.
3. Inspect all brake parts for cracks, excessive wear or
scoring. Replace brake parts as required.
ASSEMBLY
Numbers in parentheses refer to Fig. 2.
1. Install new piston seal (5) into seal groove in calliper
(7).