with a new (unused) shear adapter. In cases where a
second failure of the shear adapter confirms that the
adjustment mechanism is seized, the caliper must be
replaced.
5.2.8 Use a 10 mm., six-point box wrench (See Figure 37)
to turn the adjuster counterclockwise until sufficient
space exists to remove the brake pads. A clicking
noise occurs each time the adjuster turns.
CAUTION! Avoid overloading or damaging the adjuster
shaft. Do not use an open‑ended wrench since it may
damage the adjuster shaft.

Use these two inspections:
A. 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).
B. 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).
5.2.12 Inspect the brake rotor (See Section 4.4).
5.2.13 Inspect the guide pins (See Section 4.5).
Important: To maintain optimal braking, Bendix strongly
recommends that whenever brake pads are replaced,
the complete axle set be replaced together. Use only
pads which are permitted by the vehicle manufacturer,
axle manufacturer, and/or disc brake manufacturer.
Failure to comply with this may invalidate the vehicle
manufacturer’s warranty.
Before installing the brake pads, use the adjuster to
fully retract the tappets to provide adequate clearance.
5.2.14 Clean the surfaces that will come in contact with
the brake pad.
Caution: When installing pads and retaining springs,
where appropriate, use heavy duty gloves and always
keep fingers away from potential pinch hazard areas.
2

Figure 37 – Backing Off the Adjuster for Pad
Removal
d

oar

Inb

12

ard
tbo
Ou

Figure 39 – Pad Retaining Spring Installation

Inboard Pad
Figure 38 – Pad Removal
5.2.9 See Figure 38. Move the caliper fully inward and
remove the inboard pad, then move the caliper fully
outward and remove the outboard pad.
5.2.10 Repeat the pad removal procedure for the other
end of the axle.
5.2.11 To confirm that the guide pins are sliding freely,
examine the pads just removed for uneven wear.
24

5.2.15 Install the pad retaining springs(2) onto the brake
pads(12) by inserting one end of the spring onto
the lug at the top of the brake pad (See Figure 39).
Carefully apply enough force to permit the second
lug to fully engage, taking care to keep fingers etc.
away from the spring as it seats.
5.2.16 Pull the caliper fully outward and install the outboard
pad. Move the caliper fully inward and install the
inboard pad.
5.2.17 To reinstall wear indicators (if used): Insert the
wear sensors into position in the new brake
pads. Route the sensor cable through the cable
protection plate channel and secure the plate with
the mounting hardware retained at disassembly.
(See Section 5.2.)

5.3 C
ALIPER/CARRIER/ACTUATOR
ASSEMBLY

CAUTION: Follow all safe maintenance practices,
including those listed on page 2 of this document.
Park the vehicle (by other means than the foundation
brakes) on level ground and chock the wheels.
Figure 40 – Running Clearance Adjustment
5.2.18 Using a 10 mm., six-point box wrench, turn the
Shear Adapter (61) clockwise until the pads contact
the rotor. Note: Do not use an open-ended wrench
as this may damage the adapter. (See Figure 40).
5.2.19 Using the same tool, turn the Shear Adapter (61)
counterclockwise and listen for the sound of 3
clicks as the mechanism backs-off (increases) the
running clearance. (See Figure 37).
5.2.20 Select the correct replacement adjuster cap from
those supplied with the kit. Lightly grease adjuster
cap with Renolit HLT2 white grease (part number
14525) and install the cap.
5.2.21 Push the new pad retainer bar (11) into the groove
of the caliper. Press down on the pad retainer bar,
and insert the pad retainer pin (44), with the pin
pointing downwards, where possible. Install the
supplied washer (45) and then the spring clip (26).
(See Figure 34).
5.2.22 Apply and release the brakes. The hub should
turn easily by hand after applying and releasing the
brake.

CAUTION: When using a hoist to support the air disc
brake, do not attempt to use the pad retainer bar as a
bracing point. It is not designed to support the weight
of the brake. Use instead a brace (or chain) wrapped
around the entire brake to attach the hoist.
5.3.1 In all cases check that the current hose routing
arrangement does not restrict the full travel of the
caliper before beginning work on the assembly.
5.3.2 Remove the brake pads (See Section 5.2).
5.3.3 (See Section 5.4). If the actuator used is a spring
brake, following the manufacturer’s guidelines, cage
the spring. With all air pressure drained from the
system, disconnect the air hoses from the brake
chamber.

Vertical Mounting Bolt Style
Caliper/Carrier Assembly (Showing
Spring Brake Actuator )

Alignment
Bushing

Anchor Plate/
Torque Plate

5.2.23 Recheck the running clearance. Readjust if
necessary.
5.2.24 Reinstall the wheel, following the vehicle manual
instructions.

The brake pads and rotor must be maintained within
the recommended wear limits. Failure to monitor wear
and replace the brake pads and rotor when required
may result in diminished brake performance.

Alignment
Bushing
Mounting Bolts
(6 total - washers
not required)

Figure 41 – Vertical Mount Caliper/Carrier
5.3.4 See Figure 41. Supporting the air disc brake by
necessary means, remove the six (6) mounting
bolts/washers and discard. Note: Bendix strongly
recommends that during reassembly these bolts
are replaced – see your vehicle manufacturer for
replacement hardware. Lift the caliper up off the
anchor plate.
The vertical bolt assembly includes an alignment
bushing. This bushing must be saved for reuse during
reassembly of the brake. The bushing mounts in the
torque plate and maintains the correct alignment of the
brake assembly relative to the rotor.

25

5.3.5 If the brake assembly does not separate from the
anchor plate it may be helpful to install an M16 X 2.0
screw longer than 120 mm at the bushing locations
and tap the end of the bolt with a hammer to free
the brake assembly. Remove the assembly.

Caliper/Carrier
Assembly
(Actuator not
shown)

Axial Mounting Bolt Style

Mounting Bolts
and Washers
(6 sets total)

5.3.6 Disconnect the air hose(s) to the brake chamber.
See Figure 42. Supporting the air disc brake by
necessary means, remove the six bolts attaching
the brake to the anchor plate and remove the
caliper/carrier assembly from the vehicle.
Note: Bendix strongly recommends that during reassembly
these bolts and washers are replaced. See your vehicle
manufacturer for replacement hardware. Remove the
assembly.

Anchor Plate/
Torque Plate

Reinstallation (Both Styles)
5.3.7 Supporting the air disc brake by necessary means,
attach the brake to the anchor plate using six
(new) bolts. Torque to vehicle manufacturer’s
specifications. If torque values and bolts are not
specified by the vehicle manufacturer, then select
a replacement bolt as shown in Table 4.
5.3.8 Reinstall the air hoses (See Section 5.4.8-9) and
check for leaks.
5.3.9 Inspect and reinstall the pads (See Section 5.2).

26

Figure 42 – Axial Mount Caliper/Carrier

Air Disc Brake Attachment Hardware
Vertical Mount

Fastener & Torque

Service Actuators Shown

Fastener: M16 x 2.0 x 110 mm, Class 10.9.
Use the manufacturer’s recommendations,
but if unavailable, use a plain and oil-finish
fastener. Bendix strongly recommends
using new fasteners each time.

Left-hand Brake

Right-hand Brake

Washer: None used.
Short (floating) Pin
Sheer
Sleeve

Torque: Using the torque pattern below, pretorque to between 40-50 ft-lbf [54-68 N·m],
with a final torque 180-200 ft-lbf [244-271
N·m]

Sheer
Sleeve

Shelf

Washers are not used
on vertical-mounted ADB22X™ assemblies

Left-Hand Brake Torque Pattern (Viewed from Below)

Right-Hand Brake Torque Pattern (Viewed from Below)

Brake’s short (floating Pin) is this side

Brake’s short (floating pin) is this side

†

ƒ
‚

(view from below)

Sheer sleeve above, in this location

†
„

Shelf above, in this location

„
Shelf above, in this location

Axial Mount

Caliper/Carrier
Assembly (showing
service actuator )

ƒ
‚

(view from below)

Sheer sleeve above, in this location

Fastener & Torque
Fastener: M20 x 2.5 x 60 mm Class 10.9. Use the manufacturer’s
recommendations, but if unavailable, use a phosphate and oil-finish
fastener. Bendix strongly recommends using new fasteners each time.
Six (6) Mounting
Bolts
and Washers are
Required

Washer: Requires a HARDENED 3 mm (minimum thickness) washer
for each bolt. If the vehicle is using a Bendix manufactured axial anchor
plate, with a thickness of 1.14 in. (29 mm) at the point where these bolts
are inserted, then a bolt with an overall length of 2.36 in. (60 mm) will
meet the requirements. CAUTION: The washer outside diameter must
be less than 1.5 in (37.5 mm).
Torque: Pre-torque to 20-60 ft-lbf [27-81 N·m], with a final torque of
350-400 ft-lbf [475-542 N·m]
Torque Pattern

Anchor Plate/
Torque Plate

Any cross-pattern, see the example below:


ƒ

†„
‚

Trailer Torque Plate

Fastener & Torque

Fastener: M20 x 2.5 x L Class 10.9
Length determination:
L = Torque Plate (TP) thickness + Carrier engagement + Washer thickness
Lmin = TP thickness + 24 mm + 3 mm
Lmax = TP thickness + 29 mm + 3 mm

Use the manufacturer’s recommendations.
If unavailable, use phosphate
and oil finish fastener:
Pre-Torque: 20-60 ft-lbf [27-81 N·m]
Final Torque: 350-400 ft-lbf [475-542 N·m]

Washer: Requires THROUGH HARDENED 3 mm (minimum thickness) for each bolt.1

Table 4 – Torque Plate Fasteners and Torque Recommendations (see manufacturer’s recommendations)
27

5.4

SPRING OR SERVICE BRAKE

5.4.1 CAUTION: Follow all safe maintenance
practices, including those listed on page 2 of
this document. Park the vehicle (by other means
than the foundation brakes) on level ground and
chock the wheels.
5.4.2 Use the spring brake manufacturer’s recommended safety practices in all cases.
Some spring brake and vehicle manufacturers
permit caging the spring brake while the spring
brake is engaged.
THE FOLLOWING INSTRUCTIONS ARE FOR BENDIX®
BRAND PISTON-STYLE ACTUATORS.
5.4.3 With the vehicle on a level surface and the wheels
properly chocked, apply air to release the spring
brakes (parking brakes) by using the dash-mounted
air control valve. Back out the release bolt (See
Figure 43, arrow “D”), using a maximum torque of
26 ft-lbs (35 Nm) to cage the air released spring
force on the pushrod.
A
B
A
D

18/1

C
Figure 44 – Spring Brake Installation
CAUTION: Do not use brake chambers with seals that
have a thickness less than 0.12 in. (3 mm). Use only
actuators which are recommended by the vehicle
manufacturer.
5.4.7 Install the brake chamber using new self-locking
nuts (EN ISO 10513). Alternately tighten both the
nuts step-by-step up to a final torque of 133 ± 7 ft-lbs
(180 ± 10 Nm). Bendix strongly recommends
that new nuts be used.
5.4.8 Reconnect the air hose(s) and be sure that each
hose is not twisted or in contact with moving vehicle
components. The air hose routing must allow for full
caliper travel. Note that for spring brake service
chambers the ports are indicated by: “11” Service
Brake Port and “12” Spring Brake Port

B

Figure 43 – Actuator Spring Caging and Removal
5.4.4 Exhaust the air from the brake chambers by using
the dash-mounted air control valve. With all air
pressure drained from the system, disconnect the
air hoses from the brake chamber. While supporting
the brake chamber in position, remove and discard
the brake chamber mounting nuts (See Figure 45,
arrows marked “B”). Remove the brake chamber.
5.4.5 Reinstallation. Before installing the brake chamber,
the actuator flange (See Figure 46, arrow “C”) must be
cleaned and inspected. Consult the vehicle manual.
The spherical cup in the lever (19) must be greased
with white grease (Part No. 14525 or K021964).
Add grease to the rubber gasket on the chamber.
CAUTION: Do not use grease containing molybdenum
disulfate.
5.4.6 The seal, as well as the pushrod area, must be
clean and dry.
28

Figure 45 – Port Designations
Note: Where a new spring brake chamber is being
installed, note that in some cases drain plugs are installed
(See Figure 43, arrows marked “A”). Where drain plugs
are present, after installation, remove whichever plug is
at the lowest position. The selected drain hole must be
aligned downwards (or within ±30°) when installed on the
vehicle. In the case of spring brake chambers, install the
pads before uncaging the spring.
5.4.9 Before returning vehicle to service, with the system
pressurized, using a soap solution, check for air
leakage. Minimal leakage in the area around the
diaphragm is permitted (100 SCCM), and a one-inch
bubble in one minute at the hose fitting is acceptable.
If abnormal leakage is detected, the diaphragm must
be replaced, or fitting adjusted, respectively.

5.5

TAPPET & BOOT ASSEMBLIES, AND
TAPPET INNER SEAL REPLACEMENT

22
Inner Seal

11
Pad
Retainer

5.5.1 CAUTION: Follow all safe maintenance
practices, including those listed on page 2 of
this document. Park the vehicle (by other means
than the foundation brakes) on level ground and
chock the wheels.

13 Tappet
and
Boot
Assy

In some cases, the technician will need to remove the caliper
carrier assembly from the vehicle. (See Section 5.3.) Note
that new bolts (available from the vehicle manufacturer)
will be needed for reinstallation.

161
Tappet
Bushing

Important: If the vehicle is equipped with spring brakes,
cage the spring brakes on all axles requiring work.
Consult the vehicle manufacturer’s instructions as
necessary. This procedure may be carried out with
the air disc brake installed on, or removed from, the
vehicle. In cases where the caliper/carrier assembly
is removed from the vehicle, NEW fasteners must be
used and properly torqued during reinstallation. Use
only fasteners approved by the vehicle manufacturer.
Note: This maintenance procedure uses specialized
tools. The full Bendix® air disc brake tool kit (K029164),
or Ken-Tool® kit (80000), includes the complete set of
tools required for all permitted maintenance procedures.
Alternately, for locations where only the tappet and boot
replacement procedures will be performed, the smaller
Bendix tool kit (K028829), or Ken‑Tool kit (80001) will
suffice. The Bendix DVD (BW7356) shows this procedure.
Bendix
Number/
Ken-Tool
Number

Description

T1 / KT01

Cup

T2 / KT02

Handle for
KT01 cup

T3 / KT03

Swivel assembly
(KT03-1 short body
+ KT03‑2 brass disc
+ KT03-3 retaining
spring)

T4 / KT04

Long strut

T9 / KT09

Flange

T15 / KT015

Fork

T24 / KT024

Black Nylon Disc

Typical Tool View

Table 5 – Tappet and Boot Replacement Tools

44 Pad Retainer Pin
26
Spring Clip
45
Washer

12
Pad
Assembly

13
Tappet
and Boot
Assembly
61
Shear
Adapter
161
Tappet
Bushing
22 Inner Seal

6 Adjuster
Cap

Figure 46 – ADB Exploded and Section Views
5.5.2 Pad Removal: follow Sections 5.2.1-5.2.11 for
removal of the brake pads.
5.5.3 Inspect the Brake Rotor (See Section 4.4).

Tappet and Boot Assembly (13) Removal
CAUTION: NEVER EXTEND THE TAPPET MORE THAN
1.75 in. (44.5 mm). See Figure 47. Over-extending the
tappet will result in the tappet losing engagement with
the threads of the synchronizing mechanism. Since
the mechanism can only be set at the manufacturing
plant, the caliper/carrier assembly must be replaced
if this happens.
B

13