PREVOST X3-45 COMMUTER User Manual

SECTION 12: BRAKE AND AIR SYSTEM
44
DOB 1300-1556 | X3-45 Commuter PA-1648 Maintenance Manual Section 12 revised Jan 2021
21. Check the brake disc.
22. Check caliper running clearance (see
16.2.7 & 16.2.8).
23. Fit the brake pads.
24. Fit the brake actuator.
25. Recheck the adjuster (see 16.2.6).
If the air gap is still smaller than 0.6 mm
between both tappets, the brake caliper must be
replaced.
16.2.7 Caliper check - Caliper Running
Clearance
The Knorr Bremse air disc brake is designed to
move freely, with minimal force.
1. Before starting work, ensure that the
wheels are chocked and the vehicle can-
not roll away.
2. Ensure that service brake and parking
brake are in the released condition.
3. By pushing and pulling the caliper in an
axial direction by hand (see arrows in Fig-
ure 47), a movement of 0.6 - 1.1 mm
must be possible.
If, even using a high level of hand pressure (no
tools), the caliper is not moveable, the caliper
guide pin seals must be further examined (see
16.2.10 & 16.2.11).
Figure 47: running clearance
16.2.8 Caliper check - Caliper Movement Along
Guide Pins
1. With the open bearing variant (6b), clean
the protruding area of the guide pin (4b)
from outside of the caliper and if neces-
sary remove any light corrosion using an
emery cloth.
2. Lightly apply grease to the protruding
area of the guide pin (4b).
3. Remove brake pads.
4. Fully wind back the tappets (13) using a
ring spanner and shear adapter (61) (see
Figure 48).
FIGURE 48: REWIND TAPPETS COMPLETELY AND
PUSH CALIPER IN DIRECTION OF MIDDLE OF VIEW
5. Push caliper inboard towards vehicle’s
center (see Figure 49).
FIGURE 49: FREE GUIDE PIN OF DIRT
6. With both open bearing variants (6a and
6b), clean guide pin (4a or 4b) from the
inner area of the caliper, removing any dirt
or corrosion.
7. Lightly apply grease to guide pin (4a or
4b).
8. Caliper (1) must slide freely along the
whole length of the guide pin arrange-
ment; movement should be greater than
0.984 in / 25 mm. (see Figure 50).
If the caliper does not move at least 0.984 in /
25 mm, the caliper guide pin seals must be
examined (see 16.2.10 & 16.2.11).

PREVOST X3-45 COMMUTER Specifications

General

Engine	Volvo D13
Transmission	Allison B500
Fuel Type	Diesel
Length	45 ft (13.7 m)
Width	102 in (2.6 m)
Horsepower	500 hp
GVWR	54, 000 lbs
Height	141 in