Truck System Technologies SL7 User manual

TECHNICAL DOCUMENTATION
Doc. No. Y081564 (EN - Rev. 003)
June 2022
PNEUMATIC DISC BRAKE
SL7 - SM7
SERVICE MANUAL

2
» Y081564 - (EN - REV. 003) | JUNE 2022
Disclaimer
The information contained in this document is intended for the exclusive use of trained persons within the commercial vehicle industry, and must not be
passed on to any third party. All recommendations regarding products and their servicing or usage are with reference to Knorr-Bremse products and should
not be considered applicable to products from other manufacturers.
This information does not purport to be all-inclusive and no responsibility is assumed as a result of its use. We cannot accept any liability nor oer any
guarantee regarding data accuracy, completeness or timeliness. The information does not represent any guarantee or ensured characteristics of the Products
or Systems described. No liability can be accepted based on the information, its use, recommendations or advice provided. In no event may we be held liable
for any damage or loss except in the case of wilful intent or gross negligence on our part, or if any mandatory legal provisions apply.
Any legal disputes arising from the use of this information shall be subject to German law.
Note: If service work is carried out on the vehicle, it is the responsibility of the workshop to ensure the vehicle is fully tested and in full functional order before
the vehicle is returned into service. Knorr-Bremse accepts no liability for problems caused as a result of appropriate tests not being carried out.
This disclaimer is an English translation of a German text, which should be referred to for all legal purposes.
Revision Details
Rev. 001 August 2019 Diverse changes throughout
Rev. 002 December 2020 Double Roll Bearing variant added and layout update throughout
Rev. 003 June 2022 Small layout changes plus safety paragraph added to pages 5 and 23
Overview of Tool Kits and Service Manuals for Knorr-Bremse Air Disc Brakes
# -Refer to website for latest revision truckservices.knorr-bremse.com
Brake Tool Kit Supplemental Kit Service Manual
SB5...
SB6...
SB7...
II37951004*
K158880K50 C16352-#
SN5... K037001 Y015044-#
SN6...
SN7...
SK7...
K039062K50*
K158880K50
K209211K50 Y006471-#
SL7...
SM7...
K039062K50*
K158880K50
K209211K50 Y081564-#
ST7... K039062K50*
K158880K50 Y173241-#
*These Tool Kits are no longer produced and now replaced by Tool Kit K158880K50.
To service the new Double Roll Bearing of the caliper‘s oating bearing side, additional tools are required which are supplied in
the supplemental kit K209211K50.

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» Pneumatic Disc Brake SL7 - SM7
CONTENTS
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
1.1 Disc Brake Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.1.1 Identication of the Guide and Seal Kit Variants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2 Brake Identication and Service Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3 Brake Disc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
2. General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1 Service Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.2 Diagnostic Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.3 Lubricant. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.4 Torque Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3. Description and Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1 Disc Brake Sectioned View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
3.2 Description of Operation (Floating caliper principle) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Brake Actuation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Brake Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Brake Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4. Inspection Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 Safety Instructions for Service Work and Repair Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
5. Functional and Visual Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1 Wear Check of Pads and Brake Discs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Brake Pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Brake Disc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.2 Adjuster Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
5.3 Caliper Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
5.4 Clearance Measurement Check of Bearing Variants (6). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
5.5 Sealing Elements Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
6. Brake Pad Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.1 Removal of Brake Pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
6.2 Fitting of Brake Pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7. Tappet and Boot Assemblies (13) and Inner Seals (22) Replacement . . . . . . . . . . . . . .31
7.1 Removal of Tappet and Boot Assemblies (13). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
With caliper installed on the vehicle: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
With caliper removed from the vehicle: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7.2 Replacement of Inner Seals (22) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
With caliper installed on the vehicle: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
With caliper removed from the vehicle: (not shown):. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.3 Fitting of Tappet and Boot Assemblies (13) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
With caliper installed on the vehicle: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
With caliper removed from the vehicle: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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» Y081564 - (EN - REV. 003) | JUNE 2022
CONTENTS
8. Caliper Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
8.1 Removal of Caliper from Carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Removal of Cover (10) - Fixed Bearing Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Removal of Cap (68a; Rubber Bush or 68f Double Roll Bearing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Removal of Caliper from Carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
8.2 Fitting Caliper to Carrier - (Carrier assembled on vehicle) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Fitting of Cover (10) - Fixed Bearing Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
With Caliper (1) and Carrier (2) Fitted on the Vehicle: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Cap (68a; Rubber Bush) - Floating Bearing Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Cap (68f; Double Roll Bearing) - Floating Bearing Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Fitting of Cover (10) with Caliper (1) and Carrier (2) Removed from the Vehicle: . . . . . . . . . . . . . . . . . . . . . . . . . . 44
9. Caliper Bearings Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
9.1 Removal of Inner Boot (9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
9.2 Replacement of Brass Bush (7) Fixed Bearing Side. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Removal of Brass Bush (7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Fitting of Brass Bush (7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
9.3 Replacement of Guide Sleeve (6) Floating Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Removal of Floating Bearing Variants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
9.3.1 Removal of Guide Sleeve (6a; Rubber bush or 6b; Floating Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
9.3.2 Removal of Double Roll Bearing (6f). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Fitting of Floating Bearing Variants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
9.3.3 Fitting of Guide Sleeve (6a Rubber Bush or 6b Open Bearing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
9.3.4 Fitting of Double Roll Bearing (6f) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.4 Fitting of Inner Boot (9) Floating Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
9.5 Fitting of Guide Pin (5) Fixed Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.6 Fitting of Guide Pin (4) Floating Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.7 Engage Inner Boot (9) into Guide Pin (5) Fixed Bearing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
10.Carrier Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
11.Brake Actuator Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
11.1 Removal of Knorr-Bremse Brake Chamber. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
11.2 Fitting of Knorr-Bremse Brake Chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
11.3 Removal of Knorr-Bremse Spring Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
11.4 Fitting of Knorr-Bremse Spring Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

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» Pneumatic Disc Brake SL7 - SM7
SAFETY AND ENVIRONMENT GUIDELINES
Note: The safety advice listed below is applicable to general service and diagnostic work on braking systems. Also observe any
recommendations from the axle or vehicle manufacturer concerning towing, jacking-up and securing the vehicle.
CAUTION: KNORR-BREMSE IS NOT LIABLE FOR ANY INJURIES OR DAMAGES CAUSED BY IMPROPER USE OF SPECIFIED SERVICE KITS
AND/OR SERVICE TOOLS. FURTHERMORE, MISUSE OF TOOLS OR INCORRECT INSTALLATION OR APPLICATION OF SERVICE KITS MAY
RESULT IN DAMAGE OR POTENTIALLY UNSAFE VEHICLE OPERATIONS. IN THIS CASE, KNORR-BREMSE DOES NOT HAVE ANY WARRANTY
OBLIGATIONS.
Before and whilst working on or around compressed air systems and devices, the following precautions should be observed, along
with the many hazard notes contained throughout the document:
1 Always wear safety glasses when working with air pressure.
2 Never exceed the vehicle manufacturer’s recommended air pressures.
3 Never look into air jets or direct them at anyone.
4 Never connect or disconnect a hose or line containing pressure; it may whip as air escapes.
5 When removing or servicing a product, ensure all pressure related to the specic system it is contained in has been depleted to 0
bar. Be aware that if the vehicle is equipped with an air dryer system, it can also contain air pressure along with its purge reservoir,
if tted, even after pressure has been drained from the other reservoirs.
6 If it is necessary to drain the air pressure from reservoirs, etc., keep away from brake actuator push rods and levers since they may
move as system pressure drops. On vehicles tted with air suspension, it is advised when undertaking such work, to support the
chassis from sudden lowering and therefore prevent any possibility of being trapped between the chassis and axle or ground.
7 Park the vehicle on a level surface, apply the parking brakes, and always chock the wheels as depleting vehicle air system pressure
may cause the vehicle to roll.
8 When working under or around the vehicle, and particularly when working in the engine compartment, the engine should be
shut o and the battery disconnected. Where circumstances require that the engine be running, EXTREME CAUTION should
be taken to prevent personal injury resulting from contact with moving, rotating, leaking, heated or electrically charged
components. Additionally, it is advisable to place a clear sign on or near the steering wheel advising that there is work in progress
on the vehicle.
9 When working on vehicles equipped with air suspension, to guard against injury due to unexpected downward movement of
the chassis caused by sudden pressure loss in the suspension system, ensure that the vehicle chassis is mechanically supported
with a‘prop’between the chassis and the axle or between the chassis and the ground.
10 Examine all pipework for signs of kinks, dents, abrasion, drying out or overheating. Be aware that kinks in pipework may result in
air pressure being trapped in the pipework and associated equipment. Replacement hardware, tubing, hose, ttings, etc. must
be of equivalent size, type and strength as original equipment and be designed specically for such applications and systems.
Check the attachment of all pipework; it should be installed so that it cannot abrade or be subjected to excessive heat.
11 Components with stripped threads or damaged/corroded parts must be replaced completely. Do not attempt repairs requiring
machining or welding unless specically stated and approved by the vehicle or component manufacturer.
12 Never attempt to install, remove, disassemble or assemble a device until you have read and thoroughly understood the
recommendedprocedures.Someunitscontain powerful springs andinjury canresultif not properlydismantled and reassembled.
Use only the correct tools and observe all precautions pertaining to use of those tools.
13 Before removing any device note its position and the connections of all pipework so that the replacement/serviced device can
be properly installed. Ensure that adequate support or assistance is provided for the removal/installation of heavy items.
14 Use only genuine replacement parts, components and kits as supplied by Knorr-Bremse or the vehicle manufacturer containing
original Knorr-Bremse parts Only use the recommended tools as specied in related Knorr-Bremse instructions.
15 The serviced or replaced product must be checked for correct function and eectiveness.
16 If products have been dismantled, serviced or replaced, whose performance could aect braking performance or system
behaviour, this should be checked on a roller dynamometer. Bear in mind that a lower performance may be experienced during
the bedding-in phase if new brake pads/linings and/or brake discs/drums have been tted.
17 The use of impact screwdrivers or impact wrenches in conjunction with Knorr-Bremse service tools for air disc brakes is not
permitted. The service tools are not designed for such use. It is likely that the tools or the vehicle will be damaged and there is a
serious risk of injury – see Caution above.
18 Do not use compressed air to clean the disc brake. Avoid air contamination of brake dust.
19 Prior to returning the vehicle to service, make certain that all components and the complete brake systems are leak free and
restored to their proper operating condition.
20 Attention! During service work on vehicles with electronic parking brake, service or parking brake, or bus stop temporary hold
brake, the brake system must be set to service and maintenance mode. Please also observe the instructions of the vehicle
manufacturer.

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» Y081564 - (EN - REV. 003) | JUNE 2022
SAFETY AND ENVIRONMENT GUIDELINES
Disposal of Waste Equipment by Business Users in the European Union
This symbol on the product, packaging or in user instructions, indicates that this product must not
be disposed of with other general waste. Instead, it is your responsibility to dispose of the waste
electrical and electronic parts of this product by handing them over to a company or organisation
authorised for the recycling of waste electrical and electronic equipment. For more information about
arrangements for waste equipment disposal please contact your Knorr-Bremse distributor or local Knorr-Bremse
representative.

7
1
4
1
44
26
45 11
37
61
7
18*
58
9
12
2
6
5
40
10
39
22
13
161
» Pneumatic Disc Brake SL7 - SM7
Legend
1 Caliper*
2 Carrier*
4 Guide Pin*
5 Guide Pin*
6 Rubber Bush or Guide Sleeve* (oating bearing side)
7 Brass Bush* (xed bearing side)
9 Inner Boot*
10 Cover*
11 Pad Retainer*
12 Pad (complete)*
13 Tappet and Boot Assembly
18 Brake Actuator**
22 Inner Seal*
26 Spring Clip
37 Adjuster Cap
39 Caliper Bolt*
40 Caliper Bolt*
44 Pad Retainer Pin
45 Washer
58 Ring*
*
Variants possible
(see also contents leaet in the service kit)
** Brake chamber or spring brake
61 Shear Adapter
161 Tappet Bush
1. OVERVIEW
1.1 Disc Brake Components

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» Y081564 - (EN - REV. 003) | JUNE 2022
1.1.1 Identication of the Guide and Seal Kit Variants
* Variants possible (see also contents leaet in the service kit)
a) Rubber Bush b) Open Bearing f) Double Roll Bearing
Floating Bearing (6) variants:
5
40
9
58a
4a
4b
6a
6b
6f*
7
10
68f
68a
58f
39b
39a
39f*

9
1
KNORR-BREMSE
XXXXXX XXXXXXX
XXXXXXXXXXXXXX
X XXXXX XXXXX
KNORR-BREMSE
XXXXXXXXXXXXX
XXXXXXXXXXXXXX
XXXXXX XXXXXXX
X XXXXX XXXXX
A
A
A
A
A
A
B
B
B
C
C
C
DD
D
» Pneumatic Disc Brake SL7 - SM7
OVERVIEW
1.2 Brake Identication and Service Kits
Use only genuine Knorr-Bremse parts!
The following service kits are available:
Description Content (Position No.)
Carrier Carrier (2) 1x
For specic service part numbers allocated to the disc brake see:
truckservices.knorr-bremse.com
mytruckservices.knorr-bremse.com
Guide and Seal Kit
Guide Pin (4a,4b, 5)
Guide Sleeve (6a, 6b, 6f)
Brass Bush (7)
Inner Boot (9)
Cover (10)
Caliper Bolt (39a, 39b, 39f, 40)
Ring (58a, 58f)
Cap (68a, 68f)
Tappet and Boot Kit
Tappet and Boot (13) 2x
Inner Seal (22) 2x
Tappet Bush (161) 2x
Adjuster Cap Adjuster Cap (37) 10x
Shear Adapter (61) 10x
Brake Pads (axle set)
Pad Retainer (11) 2x
Brake Pad (12) 4x
Spring Clip (26) 2x
Adjuster Cap (37) 2x
Pad Retainer Pin (44) 2x
Washer (45) 2x
Shear Adapter (61) 2x
Caliper
Supplied without carrier (2) and without brake pads (12).
Guide Pins and Seals kit included for assembly of caliper to existing
brake carrier
Knorr-Bremse oers a range of specically
designed rationalised calipers to service a wide range of disc
brakes.
For specic caliper part number, see:
truckservices.knorr-bremse.com
mytruckservices.knorr-bremse.com
A= Axle or vehicle manufacturer’s identication number
B= Knorr-Bremse brake type number
C= Knorr-Bremse part number
D= Knorr-Bremse date of manufacture

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» Y081564 - (EN - REV. 003) | JUNE 2022
OVERVIEW
1.3 Brake Disc
Replacing brake discs is subject to the instructions of
the vehicle or axle manufacturer, including when tting
Knorr-Bremse brake discs.
When replacing brake discs, make sure to use the correct
connections and tightening torques.
The use of non-approved brake discs will reduce levels of
safety, and will not be covered by any Knorr-Bremse liability.
Knorr-Bremse recommends the brake disc be changed
as an axle set. Brake discs can be ordered through the
Knorr-Bremse aftermarket organisation.
Additionally Knorr-Bremse recommends brake discs be
changed at the latest every 6 years, even if the wear limits
have not been reached.

11
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» Pneumatic Disc Brake SL7 - SM7
2.1 Service Tools
2.2 Diagnostic Equipment
2.3 Lubricant
2.4 Torque Requirements
Part No. Description
K154433N50
A Knorr-Bremse hand-held device for checking potentiometer function
(see also Service News Y123889).
Item No. Description Torque Spanner Size (mm)
39; 40
Caliper bolts (2x)
M16x1.5 (hexagon socket head)
180 Nm plus 90° 14 (Hexagon key)
18 Brake chamber or spring brake Follow the instructions of the brake
actuator or vehicle manufacturer -
The use of impact screwdrivers / impact wrenches in conjunction with Knorr-Bremse service tools for air disc
brakes is not permitted. The service tools are not designed for such use.
Never turn the Adjuster (23) without Shear Adapter (61). If the given shear point of the Shear Adapter (61) is
reached, the adapter will fail. Try again using a brand new shear adapter. If the adapter fails a second time, the
whole caliper will need replacing due to internal damage. Do not use an open-ended spanner on the adapter as
this could damage it.
Attention: Risk of injury. Knorr-Bremse accepts no liability for damage or injury resulting from negligence; any
damage to service tools resulting from such actions will void all warranty.
Tool Description Consisting of tool components:
(A) Wedged fork for removal of tappet and boot assembly (13) T15
(C) Pull-in tool for inner boot (9) T06, T07, T08, T10
(D) Pull-in/Pull-out tool including grooving tool for brass bush (7) T08, T12, T13, T14, T16
(E) Press-in tool for tappet and boot assembly (13) T02 T03, T04, T28, T55, T56
(H) Press-in tool for cover (10) T26
(L) Press-in tool for inner seal (22) T03, T04, T09
(R) Pull-in/Pull-out tool for rubber bush (6a) and open bearing (6b) T05, T06, T18, T19,T20, T21, T22
(U) Pull-in/Pull-out tool for double roll bearing (6f) TB17, TSY01, TSY02, TSY04, TSY06, TSY07, TSY10
2. GENERAL INFORMATION
Part No. Quantity Colour Application
II14525 5g White 5.2; 7.2; 8.2; 9.2; 9.3; 9.5; 11
K093430 10g White 5.2; 7.2; 8.2; 9.2; 9.3; 9.5; 11
II32868 500g White 5.2; 7.2; 8.2; 9.2; 9.3; 9.5; 11
K125122N50 1000g White 6.2
Note: The current service tool kit (Part No. K039062K50) contains the above listed tool components for tools (A) to (R). The
supplementary tool kit K209211K50 contains the above listed tool components for tool (U).

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» Y081564 - (EN - REV. 003) | JUNE 2022
* variants
** Brake Chamber or Spring Brake
3.1 Disc Brake Sectioned View
Legend
1 Caliper*
2 Carrier*
4 Guide Pin*
5 Guide Pin*
6 Rubber Bush / Guide Sleeve
(oating bearing side)*
7 Brass Bush (xed bearing side)*
9 Inner Boot*
10 Cover*
11 Pad Retainer*
121Pad (inboard)*
122Pad (outboard)*
13 Tappet and Boot Assembly
16 Threaded Tube
17 Bridge
18 Brake Actuator**
19 Lever
20 Eccentric Bearing
22 Inner Seal*
23 Adjuster Unit
24 Turning Device
26 Spring Clip
27 Spring
30 Chain
32 Chain Wheel
33 Wear Sensor
37 Adjuster Cap
39 Caliper Bolt*
40 Caliper Bolt*
44 Pad Retainer Pin
45 Washer
46 Disc
58 Ring*
61 Shear Adapter
68 Cover*
161 Tappet Bush
3. DESCRIPTION AND FUNCTION
1* 122* 58* 9* 7* 5*
10*
23
32
61
37
27
30
17
33
24
22*
39*
6*
4*
2*1316116
26
45
11*
44
40*
13
16
46121*
68*
2027
1 12246 12119
17 18**

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3
» Pneumatic Disc Brake SL7 - SM7
DESCRIPTION AND FUNCTION
3.2 Description of Operation
(Floating caliper principle)
During actuation, the push rod of the actuator (18) moves
the lever (19). The input forces are transferred via the
eccentric roller bearing (20) to the bridge (17). The force is
then distributed by the bridge (17) and the two threaded
tubes (16) to the tappet and boot assemblies (13) and nally
to the inboard pad (12¹).
After overcoming the running clearance between the
inboard pad (12¹) and the brake disc (46), the reaction forces
are transmitted by the caliper to the outboard pad (12²). The
clamping forces on the pads and the disc (46) generate the
braking force for the wheel.
Brake Actuation
Brake Release
After releasing the air pressure, the return spring (27) pushes
the bridge (17) with the threaded tubes and lever (19) back
to the start position.
Brake Adjustment
The so called running clearance of the disc brake is the air
gap between the brake pad (12) and the brake disc (46). This
distance is necessary to achieve a free running (and therefore
unbraked) disc when the brakes are in a ‘non applied’ state.
Too large a running clearance can lead to a greater braking
distance.
The designated running clearance is so designed to
compensate for changes under typical use such as:
- expansion of parts due to high temperatures.
- viscoelastic eect of the brake pads.
- nish and runout tolerances of a brake disc and possible
lip development.
To ensure a constant running clearance between pads and
disc, the brake is equipped with a non-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 disc wear, the running clearance increases.
The adjuster (23) and turning device (24) turn the threaded
tubes (16) by an amount necessary to compensate for this
wear.

14
4
4
1
44
26
45 11
37
61
7
18*
58
9
12
2
6
5
40
10
39
22
13
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» Y081564 - (EN - REV. 003) | JUNE 2022
Despite the use of long-life materials, it is necessary to
check some of the components regularly for their general
condition. The following inspection points will ensure a
long-life and trouble-free operation of the disc brake.
Every 3 months
The pad wear must be checked visually and independent of
any wear indicator tted to the vehicle (see Sections 5.1).
With every pad replacement
It is important to check for the correct functioning of the
adjuster (see Section 5.2) and the smooth operation of the
caliper over its full range of movement (see Section 5.3). Also
inspect the tappet and boot assemblies (13), the adjuster cap
(37) and the sealing elements (9, 58) for correct tting and
condition as well as the caliper bearing in the area of the rubber
bush/guide sleeve (6) (see Section 5.3.3).
Annually
Check the caliper running clearance (see Section 5.3.1)
and the correct tting and condition of the cover (10), the
adjuster cap (37) and cover (68c, 68d or 68e) (depending on
the bearing variant).
Note: These frequencies are a minimum and, depending
on the vehicle application, a more frequent check of the
components may be necessary.
Refer also to vehicle and/or axle manufacturer’s instructions
in regard to service intervals.
The discs should be checked according to the specication
of the axle or vehicle manufacturer.
In the unlikely event of a problem, all relevant components
must be returned in order that an objective investigation of
the cause can be made.
For further information please refer to the Knorr-Bremse
Dokument Y333409.
* Variants possible
4. INSPECTION POINTS

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» Pneumatic Disc Brake SL7 - SM7
INSPECTION POINTS
4.1 Safety Instructions for Service Work and
Repair Work
Observe relevant safety instructions for service work and
repair work on commercial vehicles, especially for jacking up
and securing the vehicle.
Use only genuine Knorr-Bremse parts.
Before starting service work, ensure the service brake
and parking brake, as well as the bus stop temporary
hold brake, if tted, are not applied and that the vehicle
cannot roll away.
Screw threads and tapped holes must be free
of lubrication and residuals of thread locking
products.
After any service work:
Check the brake performance and the system behaviour
on a roller dynamometer. Check function and eective-
ness. Bear in mind that a lower performance can appear
during the breaking-in phase of the brake pads and/or
the brake disc.
Please follow service manual instructions and adhere to the
wear limits of the pads and the discs (see Section 5.1).
Use only recommended tools (see Section 2.1).
Tighten bolts and nuts to the prescribed torque values
(see Section 2.4).
After re-tting a wheel according to the vehicle
manufacturer’s recommendations, ensure that there is
sucient clearance between the tyre ination valve, the
caliper and the wheel rim, to avoid damage to the valve and
the wheel.
Observe the “Safety and Environment Guidelines” section
on pages 5 and 6.

16
A
B
A
B
D
C
D
C
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» Y081564 - (EN - REV. 003) | JUNE 2022
5.1 Wear Check of Pads and Brake Discs
For optimum safety, the pad and disc wear limits must
not be exceeded.
Brake Pads
The thickness of the pads must be checked regularly
dependent on the usage of the vehicle. The pads should be
checked corresponding to any legal requirements that may
apply. Even if a wear indicator is tted and connected, this
must be at least every 3 months.
5.1.1 Minor breakouts at the edges are permitted (see
arrow).
5.1.2 Major breakouts on the surface of the brake pad are
not permitted (see Fig.).
5.1.3 If the thickness of the friction material at its
thinnest point is less than 2 mm (dimension C) the pads
must be replaced (see Fig.).
5.1.1 - Brake pad with minor damage (permitted)
5.1.2 - Brake pad with major damage (not permitted)
5.1.3 - Brake pad thicknesses
A= Overall thickness of new brake pad 30 mm
B= Backplate 9 mm
C= Minimum thickness of friction material 2 mm*
D= Minimum allowed thickness in worn condition for
backplate and friction material 11 mm*
*If these minimum allowed thicknesses are reached, brake
pads must be replaced as an axle set.
Outboard side
Brake Pad
Outboard side
Brake Pad
Inboard side
Brake Pad
Inboard side
Brake Pad
Worn Brake Pads
New Brake Pads
5. FUNCTIONAL AND VISUAL CHECK

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5
E-F > 3,5 mm?
G-H > 2 mm?
GH
» Pneumatic Disc Brake SL7 - SM7
FUNCTIONAL AND VISUAL CHECK
5.1.4 - Exaggerated wear dierence between inner and outer brake pads
5.1.5 - Exaggerated tangential oblique wear of brake pads
Outer
Outer
Inner
Inner
Exaggerated wear dierence between inner and outer
brake pads
5.1.4 The total thickness of the friction material of the inner
and outer pad should be equal. If the dierence between the
two pads is greater then 3.5 mm (see Fig.), then the following
checks are necessary:
- Bearing clearance check (see Section. 5.3 and 5.4)
- Free movement of the brake pads in the caliper
(see Section. 5.2)
- Possible collision with other parts on the axle or
vehicle body
- Excessive dirt and grime present, if necessary
contact the vehicle manufacturer
- piping of the compressed air line
Example:
a) E=19 mm
F=15 mm > NOT OK
b) E=11,5 mm
F=13 mm > OK
Exaggerated tangential oblique wear of brake pads
5.1.5 The total thickness of the friction material at either
end of the pad should be equal. If the dierence between the
two ends is greater than 2 mm (see Fig.), then the following
checks are necessary:
- Bearing clearance check (see Section. 5.3 and 5.4)
- Free movement of the brake pads in the caliper
(see Section. 5.2)
- Possible collision with other parts on the axle or
vehicle body
- Excessive dirt and grime present, if necessary
contact the vehicle manufacturer
- Piping of the compressed air line
In addition the brake pads must be replaced (see Section 6).
Example:
1) G=21 mm
H=18 mm > NOT OK
2) G=18 mm
H=19 mm > OK
E
F

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5
M
» Y081564 - (EN - REV. 003) | JUNE 2022
FUNCTIONAL AND VISUAL CHECK
If these recommendations are ignored, there is a
danger of brake failure and therefore increased
safety risk.
Brake Disc
5.1.6 Measure the thickness of the brake disc at the thinnest
point. Be aware of possible burring at the edge of the disc.
M= Total thickness of the brake disc
New condition = 45 mm.
Worn condition = 37 mm or N = 0 mm
- the disc must be
replaced.
If the disc dimension M ≤ 39 mm
or N ≤ 1 mm , it is recommended
that all brake discs on the same axle be renewed when the brake
pads are changed.
Brake discs from Knorr-Bremse have an optical wear indicator
as a chamfer on the outer edge of the disck (N). Therefore the
brake disc wear should be checked whenever the brake pads are
checked (see Fig.).
New Brake Disc Worn Brake Disc
5.1.6 - Brake disc thicknesses and optical wear indicator
N N
M M
N N

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5
a
A1B1
D1C1
» Pneumatic Disc Brake SL7 - SM7
FUNCTIONAL AND VISUAL CHECK
5.1.7 - Tolerances and examples of cracks and grooves
on a brake disc.
If these recommendations are ignored, there is a risk
of an accident. If the brake pads and/or the brake disc
are worn down excessively, brake performance will be
reduced and may be lost completely.
Grinding of a Knorr-Bremse Splined Disc®is not
allowed.
max. 0.75 x a
max. 1.5 mm
5.1.7 Check the discs per axle at each change of pads for
grooves and cracks. If necessary replace the disc.
The gure shows possible surface conditions of the brake
disc.
A1= Small cracks spread over the surface are allowed
B1= Cracks less than 1.5 mm deep or wide, running
in a radial direction are allowed
Cracks to a max. length of 0.75 x’a’ are allowed
(a= width of the friction ring)
C1= Unevenness of the disc surface less than 1.5 mm
deep is allowed
D1= Cracks going through to the cooling duct or onto
the inner or to the outer edge of the friction ring are
not allowed and the disc MUST BE REPLACED.
The photograph shows a real-life example of such cracks and
wear grooves.
Note:
In case of surface conditions A1, B1or C1, the disc can
continue to be used until the minimum thickness A = 37 mm
is reached.
Knorr-Bremse discs are normally service-free and grinding
when changing pads is not necessary. However, grinding
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 machining must be greater than 39 mm.
In addition, the recommendations of the vehicle
manufacturer about the machining of the brake disc MUST
be followed.
C1
D1
B1

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» Y081564 - (EN - REV. 003) | JUNE 2022
FUNCTIONAL AND VISUAL CHECK
Brake Pad/Disc Wear Check (on vehicle) with bearing
variant (6b; Open Bearing)
5.1.9
The pads/disc wear can be visually determined without
removing the wheel by checking the position of the caliper (1)
compared to the xed guide pin (4).
If dimension Cis less than 1 mm (see Fig. 5.1.9b), the brake
pad thickness and the brake disc must be checked with the
wheel removed. Depending on operating conditions, it may
be necessary to check brake pad thickness and brake disc
even when dimension Cis greater than 1 mm.
If any minimal tolerance limits have been reached (see
Section 5.1) the pads and/or disc must be changed.
Brake Discs and Pads must be changed as an axle set
(see Section 6).
5.1.9a - Dimension Cwith new brake pads and disc
5.1.9b - Dimension Cwith worn disc/brake pads, to which it is a require-
ment to check pad and discs with wheel removed
Brake Pad/Disc Wear Check (on vehicle) with bearing
variant (6a; Rubber Bush and 6f; Double Roll Bearing)
For all disc brakes equipped with rubber bush type (6a/6f)
with axial ribbing (see arrow H).
5.1.8 The pads/disc wear can be visually determined
without removing the wheel, by noting the position of the
wear marker point see arrow G-the change-over point from
the ribbed to the smooth surface) (see Figs.).
If dimension Cis less than 1 mm (see Fig. 5.1.8b), the brake
pad thickness and brake disc must be checked with the
wheel removed. Depending on operating conditions, it may
be necessary to check brake pad thickness and brake disc
even when dimension Cis greater than 1 mm.
If any minimal tolerance limits have been reached (see
Section 5.1) the pads and/or disc must be changed.
Pads must be changed as an axle set (see Section 6). For disc
replacement, follow vehicle manufacturer’s recommenda-
tions.
5.1.8a - Dimension Cwith new disc and brake pads
5.1.8b - Dimension C- requires inspection of pad and discs
with wheel removed
1
4
1
CC
CC
4
GG
GG
HH
1
CC
1
CC