SECTION 12: BRAKE AND AIR SYSTEM
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
17
25. DISC BRAKES
Knorr-Bremse SN7000
disc brakes are used on
all axles. The front and drive axle discs are
actuated by 24 inch
2
effective area air brake
chambers, while on tag axle, the brake
chambers have a 16 inch
2
effective area for
service brake. The
Knorr-Bremse SN7000
brakes are supplied with automatic clearance
(slack) adjusters as standard equipment for
easier adjustment.
For more information on disc brake components
and
scheduled
maintenance,
refer
to
Knorr-Bremse Pneumatic Disc Brake SN7
Service Manual Y006471
included on your
technical publications CD.
25.1 INSPECTION
POINTS
The following inspection points will ensure long-
life and trouble-free operation of the disc brake.
IMPORTANT NOTE
Moisture and dirt is the enemy. So, as a
general recommendation, special care should
be awarded to the condition of the various
sealing elements, boots and caps to prevent
any moisture or dirt intrusion in the caliper.
Any missing or damaged sealing element,
boot or cap should be replaced immediately.
IMPORTANT NOTE
These frequencies are a minimum. Depending
on the operating conditions of the vehicle,
these inspections may need to be carried-out
more frequently.
Refer to Knorr-Bremse Y006471 Service Manual
for detailed maintenance procedures about
these inspection points.
MAINTENANCE
Every 6,000 miles:
Check brake pad wear visually. This is
independent of any electronic wear indicator
fitted to the vehicle.
Check condition of the slack adjuster cap and
sliding pin covers.
(see Knorr-Bremse Y006471 Service Manual)
MAINTENANCE
Every 12,000 miles or with every pad
replacement whichever comes first:
Check proper functioning of the slack adjuster
(see Knorr-Bremse Y006471 Service Manual)
Check that caliper operates smoothly over its
full range of movement along guide pins.
Inspect all sealing elements boots and caps.
MAINTENANCE
When replacing pads:
Check the caliper running clearance
(see Knorr-Bremse Y006471 Service Manual)
At each pad replacement, make sure the caliper
operates smoothly over its full range of
movement. If the caliper shows the following
signs, replacement of the guide sleeve (6c,
Figure 26), guide pin, screw (39) and cap is
required.
excessive or abnormal play
movement along guide pins is hard or
impossible (due to corrosion or dirt)
A missing guide pin cap
Additionally, inspect the tappet and boot
assemblies (13, Figure 26), the adjuster cap (37)
and the sealing elements (9, 58) for correct
fitting and condition as well as the caliper
bearing in the area of the rubber bush/guide
sleeve (6) (see
Knorr-Bremse Y006471
Service Manual
).
If an individual wheel has heated abnormally,
Please refer to Bendix
BW7514_Single wheel
end thermal overload checklist
. This checklist
will help you through standard verifications
required by the brake manufacturer before filing
a warranty claim.
