Removing, checking and installing rear axle brake pads

AR42.10-P-1700V

Removing, checking and installing rear axle brake pads

25.10.10

1.9.10

"Perform brake test on test bench" reference changed

Test sequence augmented/revised

 

Remove/install

Danger!

Risk of poisoning caused by swallowing brake fluid. Risk of injury caused by brake fluid coming into contact with skin and eyes.

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

Danger!

Risk of injury to skin and eyes caused by handling hot or glowing objects.

Wear safety gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A



Notes on repairs to brake system

AH42.00-P-0003-01A



Brake fluid notes

AH42.50-P-0001-01A

1

Open engine hood and raise to vertical position

AR88.40-P-1000V

2

Open brake fluid reservoir and extract some brake fluid

 In order to prevent the expansion reservoir overflowing when pressing back the brake pistons (47)

3

Remove rear wheels

AP40.10-P-4050V



Checking

4

Check brake lining thickness and brake disks (61)

 Replace brake pads (43) and brake disks (61) in complete sets if necessary.

Inspect condition of brake disks

AP42.10-P-4258V

Check brake lining thickness

 If the brake pads (43) are worn beyond the wear limit the web between the sealing groove and boot (47a) may be damaged, therefore:



AP42.10-P-4253A

Inspect brake system for leaks with pressure tester.

AR42.10-P-0015V

5

Disconnect the right rear brake pad contact sensor connector (X88/15) and pull the right rear brake pad contact sensor (S10/4) out of the brake pad (43)

Model 171.456 / 458

 Installation: Replace defective right rear brake pad contact sensor (S10/4).



Notes on installing brake pad wear sensor contact sensors

AH42.10-P-0003-01A

6

Hammer the retaining pin (41) out of the brake caliper (31) using a punch and remove spring (42)

 Installation: The arrow embossed in the retaining spring (42) must point in the direction of rotation of the wheel when driving forwards.

 Installation: Hammer in retaining pin (41) as far as the stop in the brake caliper (31).

 Model 171.473 two retaining pins (41) are fitted in each brake caliper (31).

7

Using lever (034) pry brake pads (43) out of brake caliper (31)

 Brake pads (43) are to be disposed of as special waste. The local authorities can provide information regarding whether disposal is also permitted as industrial waste similar to domestic waste.

 Installation: Only the brake pads (43) approved by Mercedes-Benz may be built-in as a set.



*123589133300



Checking

8

Check boots (47a) of brake pistons (47)

 Check boots (47a) for damage and correct seat, and replace if necessary: 

Replace brake caliper (31).

Model 171.442 /445 /454 /456 /458

AR42.10-P-0080V

Model 171.473

AR42.10-P-0080AC

9

Press back brake piston (47) using resetting device (031)

 If brake pads (43) have been removed from several brake calipers (31), their brake pistons (47) must be secured beforehand with wedges to prevent them from falling out .

 Do not fit pusher tool (031) to the brake disk (61), but push back both brake pistons (47) of a brake caliper (31) simultaneously. If brake pistons (47) are sluggish:



Replace brake caliper (31).

Model 171.442 /445 /454 /456 /458

AR42.10-P-0080V

Model 171.473

AR42.10-P-0080AC



*000589524300



*601589076300



Clean

10

Clean guide of brake pads (43) using a brake caliper brush (030).

 Do not damage boots (47a).



*000589266800

11

Coat brake paste

Except 171.473

AR42.10-P-0161-01B

 Only use the brake paste listed in the linked description and only coat this on the specified points otherwise noise complaints or damage to the brake system may occur

MB Never Sieze brake paste (gray)

*BR00.45-Z-1083-06A

12

Install in the reverse order

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

AS42.50-Z-0002-01A

13

Press brake pedal several times until the brake pads (43) touch the brake disks (61)

 Firm resistance should be noticeable at the brake pedal.



Checking

14

Check fluid level in the brake fluid reservoir, correct if necessary

AP42.10-P-4210V

Danger!

Risk of death caused by limbs being caught or crushed by rotating parts when performing tests on the brake test stand

Never leave the vehicle unattended on the rollers except in an emergency. Ensure that no one is under the vehicle or near rotating parts during testing. In case of emergency, use the EMERGENCY STOP switch to shut down test stand.

AS42.00-Z-0001-01A

15

Carry out brake test on the test stand

AP42.00-P-4290BA

Number

Designation

Order number

BR00.45-Z-1083-06A

MB Never Sieze brake paste (gray)

A 001 989 94 51 12