BENDIX SB-6-SB-7 AIR DISC BRAKE User manual

1
®
FIGURE 1 - BENDIX AIR DISC BRAKE
AIR DISC BRAKE (SB-6™ and SB-7™)
SD-23-7550
LEVER
ROTOR
ECCENTRIC
BEARING
INNERBRAKEPAD
OUTERBRAKE PAD ACTUATING BEAM
RETURN SPRINGS
ACTUATOR ROD
SUPPLY PORT
RADIAL
AXIAL

2
Index Page
1 Exploded view of brake
1.1 Axial Disc Brake Components 4
1.2 Axial Disc Brake Repair Kits 5
1.2.1 Axial Disc Brake Wear Indicator Kits 5
1.3 Radial Disc Brake Components 6
1.4 Radial Disc Brake Repair Kits 7
1.4.1 Radial Disc Brake Wear Indicator Kits 7
1.5 Brake Disc Rotor 
2 General information
(for “Axial- and Radial Disc Brake”)
2.1 Service Tools 9
2.2 Diagnostic Equipment 9
2.3 Lubrication 9
2.4 Torque requirements 9
3 Description and Function
3.1 Axial Disc Brake Sectioned View 10
3.2 Description of operation 11
3.2.1 Brake actuation 11
3.2.2 Brake release 11
3.2.3 Brake adjustment (automatic) 11
3.3 Radial Disc Brake Sectioned View 12
3.4 Description of operation 13
3.4.1 Brake actuation 13
3.4.2 Brake release 13
3.4.3 Brake adjustment (automatic) 13
4 Safety instructions for service work 13
(for “Axial- and Radial Disc Brake”)
5Brake Testing
(for “Axial- and Radial Disc Brake”)
5.1 Troubleshooting procedure 14
5.2 Adjuster check 15
5.3 Wear limits of Brake Pads and Rotor 16
5.3.1 Brake wear check using Guide Pin (for Calipers with standard Guide Pins) 18
5.3.2 Brake wear check using Guide Pin (for Calipers with long Guide Pins) 19
5.3.3 Wear Indicators 20
5.4 Diagnostic-Equipment - Hand held device ZB9031 21
5.5 Diagnostic-Equipment - Vehicle mounted device ZB9033 21
6 Pad replacement
(for “Axial- and Radial Disc Brake”)
6.1 Pad removal 22
6.1.1 Tappet Boot check 22
6.1.2 Caliper floatation check 23
6.2 Pad fitting 23
7 Tappet with Boot replacement
(for “Axial- and Radial Disc Brake”)
7.1 Tappet with Boot removal 24
7.1.1 Adjuster thread inspection 25
7.2 Tappet with Boot fitting 25
8 Caliper Suspension Sealing 27
(for “Axial- and Radial Disc Brake”)
8

3
9Guide Pin Bushing replacement 28
(for “Axial- and Radial Disc Brake”)
9.1 Brass Bushing replacement 28
9.2 Rubber Bushing replacement 28
10 Caliper replacement
(for “Axial- and Radial Disc Brake”)
10.1 Caliper removal 29
10.2 Caliper fitting 30
10.2.1 Caliper with Rubber Boot (10) 30
10.2.2 Caliper with Steel Cap (10a) 31
11 Carrier replacement 32
(for “Axial- and Radial Disc Brake”)
12 Actuation cylinder replacement
(for “Axial- and Radial Disc Brake”)
12.1 Brake Chamber removal 33
12.2 Brake Chamber fitting 33
12.3 Spring Brake removal 34
12.4 Spring Brake fitting 34
13 Additional Information
13.1 Service Video 35
13.2 Service Tool Kit 35
13.3 Diagnostic Equipment 35
Personal Notes
13.4 General Safety Guidelines 36

4
1Exploded views
VF 00127/12-ÄiO1
26
44
11
39
6*
5
7
4
958
40
10
31
37
45
18/1 18/2
1
13
161
Assembly grease (white)
Assembly grease (coloured)
12
2
31a
10a *)
*)
)
1 Caliper
2 Carrier
4 Sleeve
5 Sleeve
6Rubber Bushing
7Brass Bushing
9 Inner Boot
10 Outer Boot
10a Steel Cap
11 Pad Retainer
12 Pad
13 Tappet with Boot
18/1 Spring Brake
18/2 Brake Chamber
26 Spring Clip
31 Outer Boot Clip
31a O-Ring
37 Adjuster Cap
39 Caliper Bolt
40 Caliper Bolt
44 Pad Retainer Pin
45 Washer
58 Ring
161 Tappet Bushing
1.1 Axial Disc Brake Components
(for Wear Indicatators Kits see 1.2.1)
*) possible variants by items 10a & 31a

5
1.2 Axial Disc Brake Repair Kits
CAUTION
Use only Genuine Bendix® parts
The following Repair Kits are available
1.2.1 Axial Disc Brake Wear Indicator Kits
(Typical kits are shown below)
Type 1
Type 2
Type 4
Type 5
101 Sensor
102 Sensor
104 Cable Protection Plate
112 Clip
115 Spring Washer
116 Screw
117 Wear Indicator Cable
119 Bracket
120 Bracket
Type 3
Description Contents Association of Repair Kits to the Disc
Brakes and Repair Kit’s Order no.
Carrier Guide Kit 2, 4, 5, 31, 39, 40
Carrier Guide Kit (Steel Cap) 2, 4, 5, 10a, 31a, 39, 40
Wear Indicator Kit for variants see 1.2.1
(per axle) with or without 104
Guide Pins Kit 4-7, 9, 10, 31, 39, 40, 58
Guide Pins Kit (Steel Cap) 4, 5, 6, 7, 9, 10a, 31a, 39,
40, 58
Seal Kit for Guide Pins 9, 10, 31, 37, 58
Tappet and Boot Kit (2 pcs) 13, 161
Pad Set (per axle) 12, 26, 37, 44, 45 seewww.Bendix.com for more
Adjuster Cap (4 pcs) 37 information
Pad Retainer Kit (per axle) 11, 26, 44, 45
Pad Retainer Kit (per axle) wear sensor 11, 26, 44, 45, 104, 115, 116
Kit for Floating Pin 4, 6, 39 http://www.Bendix.com
Outer Guide Seal Kit (10 pcs) 10, 31
Kit for Fixed Pin 5, 7, 9, 10a, 31a, 40, 58
Kit for Steel Cap 10a, 31a
Screw Kit for Steel Cap 10a, 31a, 39, 40
Screw Kit for Outer Boot 10, 31, 39, 40
Exchange Caliper r.h. see Type plate
only in assembled condition
Exchange Caliper l.h. on the Caliper

6
1 Caliper
2 Carrier
4 Sleeve
5 Sleeve
6Rubber Bushing
7Brass Bushing
9 Inner Boot
10 Outer Boot
10a Steel Cap
11 Pad Retainer
12 Pad
13 Tappet with Boot
18/1 Spring Brake
18/2 Brake Chamber
26 Spring Clip
31 Outer Boot Clip
31a O-Ring
37 Adjuster Cap
39 Caliper Bolt
40 Caliper Bolt
44 Pad Retainer Pin
45 Washer
58 Ring
161 Tappet Bushing
1.3 Radial Disc Brake Components
(for Wear Indicator Kits see 1.4.1)
*) possible variants by items 10a & 31a

7
1.4 Radial Disc Brake Repair Kits
CAUTION:
Use only Geniune Bendix parts
1.4.1 Radial Disc Brake Wear Indicator Kits
(Typical kits are shown below)
Type 1
Type 2
Type 4
Type 5
101 Sensor
102 Sensor
104 Cable Protection Plate
112 Clip
115 Spring Washer
116 Screw
117 Wear Indicator Cable
119 Bracket
120 Bracket
Type 3
Description Contents Association of Repair Kits to the Disc
Brakes and Repair Kit’s Order no.
Carrier Guide Kit 2, 4, 5, 31, 39, 40
Carrier Guide Kit (Steel Cap) 2, 4, 5, 10a, 31a, 39, 40
Wear Indicator Kit for variants see 1.2.1
(per axle) with or without 104
Guide Pins Kit 4-7, 9, 10, 31, 39, 40, 58
Guide Pins Kit (Steel Cap) 4, 5, 6, 7, 9, 10a, 31a, 39,
40, 58
Seal Kit for Guide Pins 9, 10, 31, 37, 58
Tappet and Boot Kit (2 pcs) 13, 161
Pad Set (per axle) 12, 26, 37, 44, 45 seewww.Bendix.com for more
Adjuster Cap (4 pcs) 37 information
Pad Retainer Kit (per axle) 11, 26, 44, 45
Pad Retainer Kit (per axle) wear sensor 11, 26, 44, 45, 104, 115, 116
Kit for Rubber Sleeve 4, 6, 39 http://www.Bendix.com
Outer Guide Seal Kit (10 pcs) 10, 31
Repair Kit 5, 7, 9, 10a, 31a, 40, 58
Kit for Steel Cap 10a, 31a
Screw Kit for Steel Cap 10a, 31a, 39, 40
Screw Kit for Outer Boot 10, 31, 39, 40
Exchange Caliper r.h. see Type plate
only in assembled condition
Exchange Caliper l.h. on the Caliper
The following Repair Kits are available

8
1.5 Brake Rotors
(for “Axial- and Radial Disc Brake”)
When replacing the Rotors, please also refer to the instructions provided by the Vehicle Manufacturer.
They should also referred to when spec'ing Bendix Rotors.
When replacing Rotors, please adhere to the recommended bolt tightening torques.
The use of non-approved Brake Rotors will reduce levels of safety and invalidate warranty.
Brake Rotors can be ordered through any authorized Bendix parts outlet.
More information can be found on the internet at www.Bendix.com
This information booklet is also available electronically when you visit www.Bendix.com.

9
2 General Information
(for “Axial- and Radial Disc Brake”)
2.1 Service Tools
Part Number Description
ll 19252 Press-In Tool for Tappet and Boot (13)
ll 19253 Pull-In Tool for Inner Boot (9)
ll 19254 Pull-In/Out Tool for Brass Bushing (7)
II 32202 Wedged Fork for removal of Tappet and Boot (13)
II 36797 Grooving Tool for Brass Bushing (7)
Z001105 Press in Tool for Steel Cap (10a)
Item Number Torque spanner size
Ft. lbs. [Nm] in. (mm)
39 + 40 Caliper Bolts
M16x1.5 - 10.9 210±18 [285 ±25 ] 0.55 (14)
Actuator Mounting Nuts
M16x1.5 132+22 [180 +30]0.94 (24)
2.3 Lubrication
2.4 Torque requirements
2.2 Diagnostic Equipment
Part Number Description
ll 36695 ZB 9031 Hand held device for checking
Potentiometer function. ( Also Pad + Disc wear
when 13 pin chassis plug installed ).
ll 38691F ZB 9033 Chassis mounted device for measuring
Pad + Disc wear
Part Number Description Colour Application
ll 14525 Renolit HLT2 White 2)
Brass Bushing (7)
II 32793 Syntheso GL EP1 Green 2)
Rubber Bushing (6)
2) Important Note: The correct Grease MUST be used for each Bushing!
Service tool kit ZB 9032 II 37951/004EX contains the
tools listed as well as this Service manual. The
service video is available separately
as Part No. KBP2060/1, in the UK, and elsewhere as
RA-SB0002 EN.

10
1 Caliper
2 Carrier
4 Sleeve
5 Sleeve
6Rubber Bushing
7Brass Bushing
9 Inner Boot
10 Outer Boot
10a Steelcap
11 Pad Retainer
12 Pad
13 Tappet with Boot
16 Threaded Tube
17 Bridge
18/1 Spring Brake
18/2 Brake Chamber
19 Lever
20 Eccentric Bearing
22 Inner Seal Cap
23 Adjuster Unit
24 Turning Device
26 Spring Clip
27 Spring
28 Spring
30 Chain
31 Outer Boot Clip
31a O-Ring
32 Chain Wheel
33 Wear Sensor
37 Adjuster Cap
39 Caliper Bolt
40 Caliper Bolt
44 Pad Retainer Pin
45 Washer
46 Rotor
161 Tappet Bush
18/1
18/2
27
28
161
12 46 12 17 19
13 22 4 39 6
31
10
23
37
30
32
33
43
24
12
16
26
45
11
44
1
161 2
20
957
40
VF 00127/2-Äi01
31a*)
10a*)
3 Description and function
3.1 Axial Disc Brake Sectioned View
*) possible variants by items 10a & 31a

11
3.2 Description of operation
(Floating Caliper principle)
3.2.1 Brake actuation
During actuation, the Push Rod of the Actuator (18/1
or 18/2) moves the Lever (19). The input forces are
transferred via the Eccentric Bearing (20) to the
Bridge (17). The force is then distributed by the
Bridge (17) and the two Threaded Tubes (16) to the
Tappets (13) and finally to the inboard Pad (12).
After overcoming the running clearance between the
Pads and the Rotor, the reaction forces are transmit-
ted to the outboard Pad (12). The clamping forces on
the Pads (12) and the Rotor (46) generate the braking
force for the wheel.
3.2.2. Brake release
After releasing the air pressure, the two Return
Springs (27/28) push the Bridge (17) and Lever (19)
back to the start position; this ensures a running
clearance between Pads and Disc is maintained.
3.2.3 Brake adjustment (automatic)
To ensure a constant running clearance between
Disc and Pads, the brake is equipped with a low
wearing, automatic adjuster mechanism.
The Adjuster (23) operates with every cycle of actua-
tion due to the mechanical connection with Lever
(19). As the Pads and Disc wear, the running clea-
rance increases. The Adjuster (23) and Turning
Device (24) turn the Threaded Tubes (16) by an amo-
unt necessary to compensate for this wear. The total
running clearance (sum of clearance both sides of
Disc) should be between 0.03 and 0.04 in. (0.6 and
0.9 mm.; smaller clearances may lead to overheating
problems.

12
VF 00113/3-Äi01
16
22
44
26
45
11
17
1
2
97531 4010
24
33
32
30
37
43
23
13 39 4 6
161
31a*)
10a*)
VF 00113/4
27; 28 19 18/1; 18/2
46
12
20
3.3 Radial Disc Brake Sectioned View
1 Caliper
2 Carrier
4 Sleeve
5 Sleeve
6Rubber Bushing
7Brass Bushing
9Inner Boot
10 Outer Boot
10a Steelcap
11 Pad Retainer
12 Pad
13 Tappet with Boot
16 Threaded Tube
17 Bridge
18/1 Spring Brake
18/2 Brake Chamber
19 Lever
20 Eccentric Bearing
22 Inner Seal Cap
23 Adjuster Unit
24 Turning Device
26 Spring Clip
27 Spring
28 Spring
30 Chain
31 Outer Boot Clip
31a O-Ring
32 Chain Wheel
33 Wear Sensor
37 Adjuster Cap
39 Caliper Bolt
40 Caliper Bolt
44 Pad Retainer Pin
45 Washer
46 Rotor
161 Tappet Bushing *) possible variants by items 10a & 31a

13
4 Safety Instructions for service work
(for “Axial- and Radial Disc Brake”)
Please refer to the relevant safety instructions for
repair work on commercial vehicles, especially for
jacking up and securing the vehicle.
Use only Genuine Bendix parts.
Please follow repair manual instructions and adhere
to the wear limits of the Pads and the Rotors - see
Section 5.3.
Use only recommended tools - see Section 2.1.
Tighten bolts and nuts to the recommended torque
values - see Section 2.4.
After re-fitting the wheel according to the Vehicle
Manufacturer’s recommendations, please ensure that
there is sufficient clearance between the Tire Valve
Stem, the Caliper and the wheel rim, to avoid dama-
ge to the Valve.
After service work:
Check the brake performance and the system beha-
vior by actual road test.
3.4 Description of operation
(Floating Caliper principle)
3.4.1. Brake Actuation
During actuation, the Push Rod of the Actuator (18/1
or 18/2) moves the Lever (19). The input forces are
transferred via the Eccentric Bearing (20) to the
Bridge (17). The force is then distributed by the
Bridge (17) and the two Threaded Tubes (16) to the
Tappets (13) and finally to the inboard Pad (12).
After overcoming the running clearance between the
Pads and Rotor, the reaction forces are transmitted to
the outboard Pad (12). The clamping forces on the
Pads (12) and the Rotor (46) generate the braking
force for the wheel.
3.4.2. Brake release
After releasing the air pressure, the two Return
Springs (27/28) push the Bridge (17) and Lever (19)
back to the start position; this ensures a running
clearance between Pads and Rotor is maintained.
3.4.3 Brake adjustment (automatic)
To ensure a constant running clearance between
Rotor and Pads, the brake is equipped with a low
wearing, automatic adjuster mechanism. The
Adjuster (23) operates with every cycle of actuation
due to the mechanical connection with Lever (19). As
the Pads and Rotor wear, the running clearance
increases. The Adjuster (23) and Turning Device (24)
turn the Threaded Tubes (16) by an amount neces-
sary to compensate for this wear. The total running
clearance (sum of clearance both sides of Rotor)
should be between 0.03 and 0.04 in. (0.6 and
0.9 mm.; smaller clearances may lead to overheating
WARNING!
Before starting repair work, block the
wheels to ensure that the vehicle cannot
roll away, before releasing the park brake.
See Page 36 for full Safety Guidelines.
problems.

14
5 Brake Testing
(for Axial- and Radial Disc Brake)
5.1 Fault finding procedure
Lift vehicle,
turn wheel
by hand
Does wheel
turn smoothly?
Residual
pressure
within the
braking
cylinder?
NO YES
NO YES
NO YES
NO YES
NO YES
Check and if
necessary,
change or
service
preceding
braking device
END
NO YES
Running
clearance ok?
(see section 5.2)
Check adjuster
(see section 5.2)
END
Check and if
necessary,
maintain caliper
guide pins
(see section 9)
END
END
Adjuster ok?
END
Change caliper
(see section 10)
END
Tightness not
due to disc
brake
Caliper
guidance ok?
(see section 6.1.2)
Check and if
necessary,
maintain caliper
guide pins
(see section 9)
Brake pad wear
uneven?
(see note below)
Air Disc Brake
Running
clearance ok?
(see section 5.2)
Note: Difference between inboard and outboard pad less than 0.2in.(< 5mm), and diagonal wear ≤0.08in (2 mm)
NO Yes
END
FD00102EN-Äi01

15
5.2 Adjuster check
The Adjuster should be turned counter-clockwise for
2 or 3 clicks (increasing running clearance).
M+P-KN-039
23 37
M+P-KN-043
By applying the brake 5 - 10 times (about 30psi, or
2 Bar) the Box End Wrench or Socket should turn
clockwise in small increments if the Adjuster is
functioning correctly (see notes below).
If Pads are not being changed, Cap (37) should be
replaced having lightly greased it with Renolit HLT2
(available as part number II14525).
NOTE:
As the number of applications increases, incremental
adjustment will decrease.
NOTE:
If the Box End Wrench or Socket does not turn, turns
only with the first application or turns forward and
backward with every application, the automatic
Adjuster has failed and the Caliper must be replaced.
CAUTION!
Make sure that the Box End Wrench or
Socket can turn freely while
completing the following procedures.
CAUTION!
Do not overload or damage the Adjuster
(23). Use only 8mm Box End Wrench
or 1/4Ó" drive Socket with a lever length
no greater than 4in. (100mm).
DO NOT use an Open Ended Wench
since this may damage the Adjuster shaft.
WARNING!
Before starting repair work, block the
wheels to ensure that the vehicle cannot
roll away, before releasing the park brake.
See Page 36 for full Safety Guidelines.
Remove wheel.
The caliper assemply should be pushed inboard on
its guide pins. Using a suitable tool, press the inbo-
ard pad (12) away from the Tappets and check
Tappet and inboard pad backplate - it should be bet-
ween 0.02in. (0.5mm) & 0.04in. (1.0mm). If the running
clearance is too small or large, the adjuster may not be
functioning correctly and should be checked as follows.
Remove Cap (37).
M+P-KN-015
2337
1

16
5.3 Wear Limits of Pads and Rotors
Rotors
Measure thickness at the thinnest point. Avoid measu-
ring near the edge of the disc as a burr may be pre-
sent.
A = Rotor thickness (new condition) 1.77in. (45mm)
B = Rotor thickness (worn) 1.46in. (37 mm), Disc must
be replaced
C = Overall thickness of Pad (new) 1.18in. (30mm)
D = Backplate 0.35in. (9mm)
E = Minimum thickness of friction material 0.08in. (2mm)
F = Minimum allowed thickness in worn condition
for backplate and friction material 0.43in. (11mm)
(replacement of Pads necessary).
If wear dimension B ≤1.53in. (39 mm) Rotor should be
replaced together with Pads.
Wear dimension B = 1.46in. (37 mm) must not decrease. Minimum allowable thickness B=1.46in. (37 mm)
CAUTION!
Stay within the Rotor and Pad Wear Limits
Pads
The thickness of the Pads must be checked regularly
dependent on the usage of the vehicle.
The Pads should be checked to adhere to any applicable
legal requirements that may apply.
If no Wear Indicator has been connected, check for
wear at least every 3 months.
If friction material is less than 0.08in. (2mm) (see E), the
Pads must be replaced.
CAUTION!
These recommendations must be followed for proper brake performance.
M+P-KN-002
A
C
DE
B
F

17
max. 0.75 xa
max. 1.5 mm
VF 00127/3
A1B1
D1C1
a
CAUTION!
Follow these recommendations.Excessive
Pad or Disc wear will degrade optimum performance.
At each change of Pads check the Rotors for grooves
and cracks.
The diagram at the right shows possible conditions
of the surface.
A1= Small cracks spread over the surface
are allowed
B1 = Cracks less than 0.06in. (1.5mm) deep or wide,
running in a Radial direction, are allowed
C1 = Grooves (circumferencial) less than 0.06in. (1.5mm)
wide are allowed
D1= Cracks in the vanes are not allowed and the
Rotor MUST BE REPLACED.
a= Pad contact area
Note
In case of surface conditions A1,-C1, the Rotor can
remain in service until it has reached the minimum
thickness of 1.46in. (37 mm) is reached.
Knorr-Bremse Rotor are normally service-free and
refinishing, when changing Rotors, is not necessary.
However, refinishing could be useful, e.g. to increase
the load-bearing surface of the Pads, after severe
grooving on the entire friction surface has occurred.
To meet safety requirements, the minimum thickness
after refinishing is > 1.53in. (39 mm).
In addition, follow the recommendations provided by
the Vehicle Manufacturer.

18
5.3.1 Brake Wear Check using Guide Pin (For all Axial and Radial Disc Brakes except those listed in
Section 5.3.2 - These Callipers do not have the rib in position B (see also Section 5.3.2)
M+P-KN-005
CD
14
6
14
6
B
Pad conditions can be visually inspected without
removing the road wheel by noting the positon
of the Floating Pin (4) in the Caliper (1).
If dimension ‘C’is less than 0.04in. (1mm), a more
accurate check of the Pads and Disc must be
B = without rib (see also Section 5.3.2)
C = pin protrusion - shown in new condition
D = minimal pin protrusion - Pads and Rotor must be
checked with road wheel removed
If necessary change the Pads - see Section 6
completed.

19
5.3.2 Brake Wear Check using Guide Pin (Only for Axial Disc Brakes SB 7541, SB 7551 to SB 7629,
SB 7639 and Radial Disc Brakes SB 7102, SB 7112, SB 7103, SB 7113, SB 7104, SB 7114,
SB 7105, SB 7115, SB 7108, SB7118, SB 7109, SB 7119, SB 7120, SB 7130 - These Callipers do
have the rib in position B (see also Section 5.3.1)
Pad conditions can be visually inspected without
removing the road wheel by noting the positon
of the Floating Pin (4) in the Caliper (1).
If the head of the Floating Pin (4) is inside the
Rubber Bush (6) by a dimension D greater than
0.64in. (18mm), then a more accurate check of the
Pads and Rotor must be made.
If necessary, change the Pads - see Section 6.
B = with rib (see also Section 5.3.1)
C = new condition
D = 0.64in. (18mm) or more, Pads and Rotor must be
checked with road wheel removed
M+P-KN-006
14
6
C
D
14
6
B

20
5.3.3 Wear Indicators
There are two types of Pad Wear Indicators available
to accommodate the differences in vehicle types and
manufacturers, including:
a) In - Pad Normally Closed Indicator - Circuit is
broken when Pad Wear reaches the limit.
b) In - Pad Normally Open Indicator - Circuit is
made when Pad Wear reaches the limit.
c) Wear Indicator using built in Potentiometer. This
is available either as an on/off version or
as a continuous signal version which can be
linked to the vehicle’s electronic monitoring
systems.
An optical or acoustic device may be linked to any of
the above.
Important
Please refer to the specifications provided by the
Vehicle Manufacturer
M+P-KN-007
M+P-KN-008
See Figure to the right.