Bendix Commercial Vehicle Systems ADB22X-V Air Disc Brakes - Manual (Page 12)

12
4.3- 4.4 BRAKE PADS AND ROTORS
CAUTION: Follow all safe maintenance practices.
If electronic wear sensors are present, see Section 5.2.
If dust covers are present, see Section 5.1.
See Figure 23. While pressing down against the pad
retaining bar (11), remove and retain the clip (26),
washer (45) and pin (44). Remove the pad retainer bar (11).
Bendix recommends that these items should be replaced
with new (See available kits and parts, Section 5.0).
Follow the steps in Section 4.2 for backing-off the adjuster
mechanism. Slide the caliper inboard then outboard to
permit easy removal of the brake pads.
A Thickness of a new pad (1.181 in.) (30 mm.).
B Backing plate thickness (0.360 in.) (9 mm.)
C Minimum thickness of friction material (0.080 in.)
(2 mm.)
D Minimum thickness of a worn pad (0.433 in.)
(11 mm.); replace pads.
E Thickness of a new rotor (1.77 in.) (45 mm.).
Minimum rotor thickness (1.46 in.) (37 mm.)
Outboard
Brake Pad
Inboard
Brake Pad
Brake Rotor
FIGURE 22 - PAD AND ROTOR DIMENSIONS
See Figure 22 for initial brake pad and rotor dimensions,
as well as minimum acceptable dimensions.
44
Pin
26 Spring Clip
45 Washer
11 Pad Retainer Bar
FIGURE 23 - RETAINER BAR REMOVAL
4.3 INSPECT THE BRAKE PADS
Regular inspection of the brake pads (even for vehicles
that use an electronic wear indicator) is an important part
of vehicle maintenance.
4.3.1 See Figure 22. If the thickness of the friction
material — dimension “C” — is less than 0.080 in.
(2 mm.), the pads must be replaced.
Bendix ® ADB22X ™ , ADB22X-V ™ air disc brakes use 0.35 in.
(9 mm.) backing plates, so dimension “D” (the combined
pad and backing plate thickness) must be a minimum of
0.43 in. (11 mm.).
4.3.2 Check for uneven end-to-end pad wear. If the
difference in wear is greater than 0.080 in. (2 mm.),
replace the brake pads and also inspect the guide
pins (See Section 4.5).
4.3.3 Compare the thickness of the inboard and outboard
pads of each set. If the difference between the
inboard and outboard pad thickness is greater than
0.138 in. (3.5 mm.), replace the brake pads and
inspect the guide pins (See Section 4.5).
If the results of the pad inspections are within the acceptable
range, inspect the pad surface. (See Figure 24).
Minor Damage -
Is Acceptable
Where a
small amount
of brake
material
chipped from
the edge
Major Damage -
Is Not Acceptable
Section
damaged or
missing
FIGURE 24 - BRAKE PAD SURFACE INSPECTION
Minor damage at the edges is permitted, but replace the
pads if major damage on the surface of the pad is found.
When replacing brake pads, Bendix strongly recommends
that all the brake pads on an axle be replaced at one time.
See Section 5.1 for the pad replacement procedure. Also
see the vehicle manufacturer’s recommendations found in
the operator’s manual.