notches for identification. With ZOH-T calipers,
install the solid pin (no bushing) only in the an-
chor plate leading hole position. Install the pin
with the rubber bushing and notches only in the
anchor plate trailing hole position. Tighten the
leading-side pin first, then tighten the trailing-
side pin.
Tighten ZOH-T bolts 93 to 107 lbf·ft (126 to 145
N·m). Tighten ZOPS bolts 70 to 80 lbf·ft (95 to 108
N·m).
42–15 Brake Caliper Slide Rail
Lubricating, Bosch
Brakes
1.
Raise the vehicle off of the ground and securely
support it with jack stands.
2.
Remove the wheel from each wheel end. For
instructions, see Group 40 of the
School Bus
Chassis Workshop Manual
.
3.
Place a stool near the axle to rest the caliper
upon after it is removed.
4.
Remove the key retainer screw from the anchor
plate.
5.
Using a hammer and drift, carefully drive out the
key and spring. Be careful not to nick the anchor
plate rail.
6.
Insert a large flat-bladed screwdriver through the
caliper vent window and into the rotor fins. Pry
the caliper outward; this will push the pistons
back slightly into the caliper, making removal
easier.
7.
Grasping the caliper, swing it out and lift it from
the anchor plate. Rest the caliper on the stool.
For ease of removal, swing the caliper on the
forward anchor plate torque rail (the large one
opposite the key and spring rail).
8.
Carefully remove the brake pads to avoid dam-
age or getting grease on the pad face. Set them
aside.
9.
Using brake cleaner or alcohol, remove old
grease and road accumulation from the caliper
V-ways, the anchor plate rails, and the shoe
slots. Also clean the key and spring.
10. Using a wire brush or wire wheel, remove any
remaining debris from the V-ways, rail, shoe
slots, key and spring.
11. Inspect the caliper to ensure that the piston
boots are in good condition with no punctures or
tears and are properly seated in the caliper.
Check to see that the heat shields are properly
seated. Repair or replace them if necessary.
12. Inspect the brake hoses for twists, cracks, blis-
ters or abrasions, and replace them as neces-
sary.
f422357
06/20/2002
1
2
3
4
1.
Flanged Bolt
2.
Leading Pin
3.
Trailing Pin
4.
Rubber Bushing
Fig. 7, ZOH-T Slide Pins and Bolts
f422358
06/20/2002
1
3
3
2
1.
Hexbolt
2.
Blue Patch
3.
Slide Pin
Fig. 8, ZOPS Slide Pins and Bolts
Brakes
42
School Bus Chassis Maintenance Manual, March 2003
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