PREVOST X3-45 2016, Maintenance Manual

Page: 249 / 459

Section 12: BRAKE AND AIR SYSTEM
Section 12 Updated Sept. 2015 X3-45 Commuter PA1593 DOB 2400-2489
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only enough to stop leakage. Do not
overtighten as this can distort sealing
surface or clamping ring. Coat area around
push rod hole (loosen boot if necessary). No
leakage is permitted. If leakage is detected,
the diaphragm must be replaced.
30.2 EMERGENCY/PARKING BRAKE
MANUAL RELEASE
DANGER
Never stand in the axis line of the spring brake
chambers, especially when caging the spring.
Drive Axle
1. Block the wheels to prevent the vehicle from
moving.
2. Screw-out the spring brake release bolt
(arrow) with a maximum of 26 lbf-ft (35 Nm)
to the release position.
3. To manually reset the emergency/parking
brake, screw in the spring brake release bolt
with a maximum of 52 lbf-ft (70 Nm).
30.3 BRAKE CHAMBER REMOVAL
WARNING
To prevent personal injuries, brakes should be
inoperative prior to working on any of their
components.
To prevent personal injuries, brake chambers
should be made inoperative by releasing
spring tension prior to disposal.
1. Block the wheels to prevent the vehicle from
moving.
2. Safely support vehicle at the recommended
body jacking points.
3. To gain access to a given brake air
chamber, the corresponding wheel can be
removed (refer to Section 13: "Wheels, Hubs
and Tires" ).
4. Exhaust compressed air from system by
opening the drain valve of each reservoir.
5. For the drive axle brake chambers, manually
release spring brakes (refer to
" Emergency/Parking Brake, Manual
Release" procedure in this section).
6. Disconnect air line(s) from brake chamber.
7. Remove the cotter pin connecting brake
chamber and slack adjuster (drive axle).
8. Unbolt and remove the brake chamber from
vehicle.
30.4 BRAKE CHAMBER INSTALLATION
Reverse removal procedure and then check
brake adjustment.
CAUTION
Always clean air lines and fittings, and coat
pipe threads with teflon pipe sealant before
reconnecting air lines.
30.5 BRAKE CHAMBER DISASSEMBLY
DANGER
Spring brake chambers, on drive and tag axles
contain an extremely high compressive force
spring, which can possibly cause serious injury
if special precautions are not taken when
working around this area.
To avoid such injury, the following recommen-
dations must be applied:
o Prevost recommends the installation of a
new spring brake chamber if it is found to
be defective.
o Spring brake chamber maintenance and/or
repair must be performed by trained and
qualified personnel only.
o
Before manually releasing spring brakes,
visually check spring brake for cracks
and/or corrosion.
o On “MGM” brake chambers (drive axle),
make sure the release stud is properly
anchored in spring plate receptacle prior to
caging the spring.
o Never stand in the axis line of the spring
brake chambers, especially when caging
the spring.