Note: Axles should
have either all Bendix
Splined Disc (or all
conventional) rotors.

Figure 25 – Examples of Acceptable and Non-acceptable Rotor Conditions
17

4.4.3 Machining (Grinding or Turning) Rotors
Bendix brand rotors are normally service-free. In the
case of severe grooving of the entire friction surface,
however, CONVENTIONAL ROTORS may be turned
when changing pads, to increase the load-bearing surface.
Machining of BENDIX® SPLINED DISC® rotors is not
permitted.
®

1
Caliper

9
Inner
Boot

7
Brass
Bushing

5
Guide Pin

10
Cap

LONG
BEARING
SIDE

CAUTION: Always maintain air disc brake pads and rotors
within specifications. Excessive pad or rotor wear will
degrade braking performance.
Periodic inspection of the Bendix Splined Disc attachment
hardware is recommended to ensure optimum braking
performance. Bendix recommends verifying the torque on
the spring element fasteners whenever a brake inspection
is performed.

A F TER M ACHI NI NG/ TURNI NG, THE M I NI MUM
ROTOR THICKNESS FOR CONVENTIONAL BENDIX®
BR AND ROTORS MUST BE AT LE AST 1.535 1.575 IN. (39 - 40 MM). FOR OTHER BR ANDS,
CONSULT THE MANUFACTURER’S GUIDELINES.
ALSO, CHECK THE VEHICLE MANUFACTURER’S
RECOMMENDATIONS. FAILURE TO COMPLY MAY
RESULT IN BR AKE FAILURE AND IN SERIOUS
INJURY OR DE ATH. MACHINING OF BENDIX
SPLINED DISC ROTORS IS NOT PERMITTED.

SHORT
BEARING
SIDE

6 Guide Sleeve
Outboard

Inboard

68
Cap

39
Caliper Bolt

4.4.4 Rotor Replacement
An axle is permitted to have only all Bendix Splined
Disc or all conventional rotors.

Caliper
Movement

9 Inner Boot

4 Guide Pin

Figure 26 – Guide Pins

When replacing rotors, be sure to adhere to the vehicle
manufacturer’s recommendations, including bolt tightening
torques. It is recommended to install only Bendix brand
rotors, and also that the pads should be replaced (as an
axle set) at the same time.

12 Pad Assembly

1
Carrier

Non-Bendix brand rotors. If a non-Bendix brand rotor is
used, confirm that it complies to the vehicle manufacturer’s
recommendations.
CAUTION: The use of non-approved brake rotors may
reduce levels of safety and invalidate the warranty.
See Section 5.7 for reinstallation procedures.

Magnetic
Dial‑Gauge
Measures
Range Here

2
Caliper

4.5 GUIDE PIN BEARING INSPECTION

Figure 27 – Magnetic Dial-Gauge In Use

CAUTION: Follow all safe maintenance practices.

4.5.1 Remove the Pads (See Section 4.3). The caliper
should slide using no more than 200 N (45 lbs) of
force along the whole length of the guide pins. A
force gage may be used to help measure this more
accurately. This movement should be at least 0.95
inch (25 mm) when the pads are not present. If the
movement is less than this amount, replace the
caliper/carrier assembly.

This guide pin inspection should be carried out if the
technician cannot move the caliper. See Section 4.1.
Measure the range of travel along the guide pin
bearings:

18

Measure the “play” (range of movement) in the guide
pin bearings:
4.5.2 See Figures 26 and 27. With the wheel removed,
remove the pad retainer (11). Temporarily replace
the pads with two new pads (12). Attach a magnetic
dial-gauge holder to the carrier (2) on the short
bearing side of the caliper (1). Use the measuring
point on the caliper (1) – see the callout in Figure
27. Press the caliper in the direction of the carrier
(2) and set the dial-gauge to zero.
4.5.3 Place a suitable tool (e.g. a large flat-blade
screwdriver) between the carrier (2) and the caliper (1)
and use light hand force to move the caliper away
from the carrier, until the movement stops. Read the
maximum value on the dial-gauge. See Figure 27.
If the value is greater than 0.039 in. (1.0 mm), replace
the guide pin bushings (See Section 5.6) OR replace the
caliper/carrier assembly (See Section 5.3).
Inspect the guide pin inner boots:
4.5.4 See Figures 28 and 29. With the pads removed,
slide the carrier by hand to the inboard position
(See Figure 28). By looking through the opening
where the pads are installed – and also from
below – inspect the inner boot (9) for each of the
guide pins. INSPECT FOR DAMAGE, CUTS,
A N D C R A C K S. Replace damaged boots
immediately to prevent dirt and/or moisture affecting
the movement of the guide pins (See Section 5.4).
Damaged or corroded guide pins will impair the
operation of the brake.
In addition, during installation, the boots are
compressed to minimize the amount of air trapped
within them. Observe as you move the carrier back
towards the outboard position; the boots should only
expand outwards a small amount due to trapped
air. The boots should normally (due to their ribbed
construction) contract back into place as the caliper
moves on the guide pins. The boots are not air-tight
and so some trapped air is normal; excess trapped
air will dissipate.

4.5.5 Inspect the original pads (See Section 4.3) and they
may be reused if they are in good condition with
sufficient pad thickness.

4.6 TAPPET AND BOOT ASSEMBLY
INSPECTION

4.6.1 In order to inspect the tappet and boot assembly,
remove the pads (12) (See Sections 4.3 or 5.2) and
advance the shear adapter (61) clockwise.
CAUTION: NEVER EXTEND THE TAPPET MORE
THAN 1.75 in. (44.5 mm). (See Figure 29). Overextending the tappet will result in the tappet losing
engagement with the synchronizing mechanism. Since
the mechanism can only be set at the manufacturing
plant, the caliper/carrier assembly must be replaced
if this happens.
4.6.2 I N S P E C T T H E T A P P E T A N D B O O T
A S S E M B L I E S (13) F O R E V I D E N C E O F
DAMAGE, CUTS, CRACKS, TEARS, AND
EVIDENCE OF CORROSION, ETC. Damaged
boots lead to the penetration of dirt and moisture,
and can promote corrosion and impair the operation
of the brake. Replace as necessary (See Section
5.5).

13

Extend LESS THAN
1.75 in. (44.5 mm)
Figure 29 – Permitted Tappet Extension
Where the tappets and boots pass the inspection, retract
the tappets using the shear adapter.

Inspect
Boot

Figure 28 – Guide Pin Boot Inspection (This Image
Does Not Show the Carrier)

When installed, the boots are compressed to minimize the
amount of air trapped within them. Observe as you move
the tappet back using the shear adapter; the boots should
only expand outwards a small amount due to trapped air.
The boots should normally (due to their ribbed construction)
contract back into place as the tappets move. Note: If the
bellows have excess trapped air, then with the tappets
retracted, remove and re-install the actuator to vent the
excess trapped air (See Section 5.4).
Follow the reinstallation steps for the brake pads (See
Section 5.2).
19

SECTION FIVE: MAINTENANCE KITS AND PROCEDURES
Section

5.0
5.1
5.2
5.3

Page

Maintenance Kits . . . . . . . 20-23
Air Disc Brake Shield Kit . . . . .
23
Pad Replacement . . . . . . .
24
Caliper/Carrier/Actuator Assembly . 27-29

Section

Page

5.4
Spring or Service Brake . . . . . . 30
5.5 Tappet & Boot Assemblies, and
Tappet Inner Seal . . . . . . . 32-36
5.6
Guide Pin and Boot Assemblies . . 37-42

(Wheel turns
Type B toward fixed pin
side of ADB)
11 Pad Retainer
44
Pad Retainer Pin

Type A
(Fixed pin)

35

18/1 Spring Brake
Actuator
18/2
Service
Actuator

26 Spring Clip
12/2 Pad Holder Spring
45
Washer

Wheel Rotation
(typically left
hand)

Wheel Rotation
(typically right
hand)

(Note: Pad Assembly
10
consists of 12/1 plus 12/2)
40 Cap
12/1 Pad
5 Caliper
Guide Bolt
Pin
7
Brass
Bushing

22
Inner Seal

Shield
Kit
(Drive or
Steer)

161
Tappet Bushing
13 Tappet
and Boot
Assembly

U-shaped Rotor

68
Cap
39 Caliper Bolt

Actuator
Hardware

61 37*
Shear
Adapter

4 Guide Pin
6 Guide Sleeve
Carrier
Mounting
Hardware

1
Caliper
(or Caliper Kit)

9
58 Inner Boot
Ring

*37 Adjuster
Caps (2 styles
supplied in kits)

Bendix® ADB22X®
Anchor Plate
2A
Bendix®
ADB22X®
Carrier

(Rotor Shield for Trailers)
U-shaped
Rotor
Fasteners

2B
Bendix®
ADB22X®-V
Carrier

SD-1
Drive Hub

SD-3

Splined Disc
Rotor (SD)

SD-2
Splined Disc®
Rotor Hardware
SD-1, -2, -3

Bendix
ADB22X-V
Anchor
Plate

Carrier
Mounting
Hardware

See Section 5.2 for
exploded view of electronic
wear indicator.

Steer Hub

Figure 30 – Exploded View - Bendix ® ADB22X®, ADB22X® -V , and ADB22X® -LT Air Disc Brakes
20

5.0 MAINTENANCE KITS FOR BENDIX ® ADB22X ®, ADB22X ®-V, AND ADB22X ®-LT AIR
DISC BRAKES
Below is a list of some of the available kits. See Figure 30 for an exploded view showing the components listed.
Kit

Piece Number

Components Included in Kit

K109113
K129276

BX283+™ Kit (11, 12/1, 12/2, 26, 37, 44, 45, 61) Severe Service
BX276™ Kit (11, 12/1, 12/2, 26, 37, 44, 45, 61) Trailer and Truck

K162216

BX275 Kit, Wear Sensing (11, 12/1, 12/2, 26, 37, 44, 45, 61, 101, 104, 106)
Standard Service

K162217

BX276 Kit (11, 12/1, 12/2, 26, 37, 44, 45, 61, 101, 104, 106) Trailer and Truck

K162218

BX283+ Kit, Wear Sensing (11, 12/1, 12/2, 26, 37, 44, 45, 61) Severe Service

K182236

BA236™ Kit (11, 12/1, 12/2, 26, 37, 44, 45, 61) Standard Service

Pad Kit (axle set)
Wear Sensing
Version 1

K162217

BA276 Kit (11, 12/1, 12/2, 26, 37, 44, 45, 61, 101, 104, 106) Standard Service

K162218

BA283+ Kit (11, 12/1, 12/2, 26, 37, 44, 45, 61, 101, 104, 106) Severe Service

Pad Kit (axle set)
Wear Sensing
Version 2

K196276

BA276 Kit (11, 12/1, 12/2, 26, 37, 44, 45, 61, 101, 104) Standard Service

K196283

BA283+ Kit (11, 12/1, 12/2, 26, 37, 44, 45, 61, 101, 104) Severe Service

K162789

Wear Sensing ECU, 250K Baud Rate, In Pad Wear Sensing, With Velcro

K162791

Wear Sensing ECU, 500K Baud Rate, In Pad Wear Sensing, With Velcro

K163396
K192257
K192258
K193988
803151

Supply Line 1.5 Meter, In-Pad Wear Sensing Version 1 (103)
Supply Line 1.5 Meter, In-Pad Wear Sensing Version 2 (103)
Supply Line 1.0 Meter, In-Pad Wear Sensing Version 2 (103)
Supply Line 0.75 Meter, In-Pad Wear Sensing Version 2 (103)
(26)

Pad Kit (axle set)

Wear Sensing ECU

Wear Sensing Supply Line
Splint Kit (box of 25)
Shear Adapter (box of 10)

802455

Tappet/Boot Kit (wheel end kit)

K092079

Adjuster Cover (box of 10)
Guide Pin, Seal, and Boot Kit
(wheel end kit)

802643

(37)

803114

(4, 5, 6, 7, 9, 10, 37, 39, 40, 58, 61, 68)

II14525

White (5 grams)

Guide Pin Grease

Service Actuators
(See Warning on page 3)

NG-3 Piston-Style
Spring Brake Chambers
(See Warning on page 3)

Double-Diaphragm-Style
Spring Brake Chambers
(See Warning on page 3)

Caliper-Carrier Assembly
(Includes 803114)

Table 2 – Maintenance Kits

(61)
(13, 22, 161)

K021964

White (500 grams)

K028039

Bendix® Type 14 Universal (9, 18/2)

K028226

Bendix® Type 16 Universal (9, 18/2)

K028022

Bendix® Type 18 Universal (9, 18/2)

K028225

Bendix® Type 20 Universal (9, 18/2)

K028238

Bendix® Type 22 Universal (9, 18/2)

K028252

Bendix® Type 24 Universal (9, 18/2)

K027557

Bendix® Type 18/16 Piston Style Truck/Trailer Universal (1, 18/1)

K025670

Bendix® Type 18/24 Piston Style Truck/Trailer Universal (1, 18/1)

K025669

Bendix® Type 20/24 Piston Style Truck/Trailer Universal (1, 18/1)

K042457

Bendix® Type 16/24 Double-Diaphragm-Style (35)

K132352

Bendix® Type 18/24 Double-Diaphragm-Style (35)

K041960

Bendix® Type 20/24 Double-Diaphragm-Style (35)

K043148

Bendix® Type 22/24 Double-Diaphragm-Style (35)

K043270

Bendix® Type 24/24 Double Diaphragm-Style (35)

K081142

Bendix® ADB22X® 12° Steer and Drive Axial “A” (2A, 1)

K081143