Remove/install brake shoes at rear axle

AR42.10-P-0165SR

Remove/install brake shoes at rear axle

16.02.2017

Model

453

Modification notes

12.01.2016

Document revised completely.

1

Brake shoe

5

Spring

10

Spring

2

Clamping spring

6

Brake cover plate

11

Contact surfaces

3

Retaining pin

7

Wheel brake cylinder

12

Support bushing

4

Brake cable

9

Parking brake lever

13

Slack adjuster

13.2

Bimetal locking clip

13.4

Adjusting nut

13.1

Brake shoe mounting

13.3

Adjustment plate

 Danger

Risk of accident when commissioning the vehicle due to a lack of braking effect when the service brake is operated for the first time after repair work.

Before starting the engine, actuate brake pedal several times until pressure is built up and maintained in the brake system.

AS42.50-Z-0002-01A

 Caution

Risk of poisoning from swallowing brake fluid. Risk of injury from skin and eye contact with brake fluid

Only pour brake fluid into suitable and appropriately marked containers. Wear protective clothing and eye protection when handling brake fluid.

AS42.50-Z-0001-01A

Topical note

Notes on repairs to brake system

AH42.00-P-0003-01A

Topical note

Brake fluid notes

AH42.50-P-0001-01A



Remove

1

Remove brake drum

AR42.10-P-1010SR

2

Remove clamping springs (2) and remove retaining pins (3)

3

Pull brake shoes (1) one after the other out of the support bushing (12), tilt slightly upwards and position on support bushing (12)


The spring (5) may not be stretched.
Otherwise, the brake may suffer damage or malfunction.

4

Detach spring (5) and remove

 Note the installation position.

5

Unhook brake cable (4) from parking brake lever (9)

6

Tilt brake shoes (1) upwards over the wheel hub, push piston of wheel brake cylinder (7) together and remove brake shoes (1) with spring (10) and slack adjuster (13)


Carefully guide brake shoes (1) over dust boots of wheel brake cylinder (7).
If a dust boot is damaged, the wheel brake cylinder (7) must be replaced.

7

Detach spring (10) and slack adjuster (13) from brake shoe (1)

 Note installation position of spring (10) and slack adjuster (13).



Clean

8

Clean brake cover plate (6)



Check

9

Check wear and condition of brake shoes (1)


The parking brake lever (9) must operate smoothly.
Otherwise, the parking brake will be difficult to operate or it may not release.


The brake lining of the brake shoes (1) must be absolutely free of grease.
Otherwise the braking effect will be impaired.

Brake lining thickness

*BE42.10-P-1002-12E

In the event of complaints



Replace brake shoes (1) on each axle.

10

Check ease of movement of pistons and leak tightness of wheel brake cylinder (7)

In the event of complaints



Replace wheel brake cylinder (7).

AR42.10-P-0167SR


In the event of even the slightest signs of brake fluid leaks or sluggishness of the pistons of the wheel brake cylinder (7) this must be replaced.
Otherwise, the braking effect may be impaired.

11

Check slack adjuster (13) for damage

In the event of complaints



Replace slack adjuster (13).

12

Check bimetal locking clip (13.2)

 The bimetal locking clip (13.2) must be located in unloaded state under the hook of the slack adjuster (13) (arrow B).
When under load, the bimetal locking clip (13.2) must be capable of being pushed into the hook (arrow C). If the slack adjuster (13) is relieved, while the bimetal locking clip (13.2) is in the hook, the bimetal locking clip (13.2) must hold the slack adjuster (13) in place.

In the event of complaints



Replace slack adjuster (13).

13

Check adjuster mechanism of slack adjuster (13) by pushing together and then releasing again

 The adjusting nut (13.4) must turn easily and reliably when the brake shoe mounting (13.1) is held in place by the adjusting plate (13.3).

In the event of complaints



Replace slack adjuster (13).



Install

14

Set slack adjuster (13) back slightly, by screwing-in the brake shoe mounting (13.1)


Do not screw brake shoe mounting (13.1) all the way in or tighten it.
Otherwise, reliable adjustment is no longer assured.

15

Coat contact surfaces (11) and contact surfaces on slack adjuster (13) with thin coating of brake paste

MB Never Seeze brake paste (gray)

*BR00.45-Z-1083-06A

16

Mount spring (10) and slack adjuster (13) to brake shoes (1)

 Note installation position of spring (10) and slack adjuster (13).
The longer part (arrow A) of the brake shoe mounting (13.1) must be located on the outside of the brake shoe (1) with the parking brake lever (9).

17

Push piston of wheel brake cylinder (7) together, mount brake shoes (1) with spring (10) and slack adjuster (13) onto piston of wheel brake cylinder (7), tilt downwards over wheel hub, and position on support bushing (12)


Carefully guide brake shoes (1) over dust boots of wheel brake cylinder (7).
If a dust boot is damaged, the wheel brake cylinder (7) must be replaced.

18

Hook brake cable (4) into parking brake lever (9)

19

Attach spring (5)

 Note the installation position.

20

Position brake shoes (1) one after the other into the support bushing (12)


The spring (5) may not be stretched.
Otherwise, the brake may suffer damage or malfunction.

21

Insert retaining pins (3) and install clamping springs (2)

22

Install brake drum

AR42.10-P-1010SR

Test and adjustment values for drum brake

Number

Designation

Model 453.3/4

Model 453.0

BE42.10-P-1002-12E

Brake lining thickness

New

mm

4,2

4,2

Wear limit for maintenance service

mm

2,4

2,4

Pad backing plate

mm

2,0

2,0

Repair materials

Number

Designation

Order number

BR00.45-Z-1083-06A

MB Never Seeze brake paste (gray)

A 001 989 94 51 12