SECTION 12: BRAKE AND AIR SYSTEM
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
25
Check all hoses and lines. They should be
secure and in good condition.
Every 100,000 Miles (160 000 km) or once a
year, whichever comes first depending on
type of operation:
1. Disassemble and clean all parts.
2. Install new diaphragm or any other part if
worn or deteriorated.
NOTE
When the diaphragm, spring, or both are
replaced, they should be replaced in the
corresponding chamber on the same axle.
3. Perform an airtighteness test:
a) Make and hold a full brake application.
b) Coat clamping ring(s) with a soapy solution.
If leakage is detected, tighten clamping ring
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.
28.2 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).
28.3
BRAKE CHAMBER REMOVAL AND
INSTALLATION
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.
Use the following steps in conjunction with
Brake Actuator Replacement procedure found in
Knorr-Bremse Pneumatic Disc Brake
SN7
Service Manual Y006471.
Removal
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. Unbolt and remove the brake chamber from
vehicle.
Installation
1. Reverse removal procedure and then check
brake adjustment.
FIGURE 40: TYPICAL AIR CHAMBER MOUNTING NUTS
TORQUE – ZF A132 DRIVE AXLE SHOWN
