Removing, checking and installing rear axle brake pads

AR42.10-D-1700FC

Removing, checking and installing rear axle brake pads

06.03.2020

Model

909.64

Model

909.8

Shown on model 909.8 on left side of vehicle

1

Caliper support

2

Brake linings

3

Retaining springs

4

Brake caliper

5

Screws (2 ea.)

6

Brake wear sensor

Shown on model 909.8 on left side of vehicle

4

Brake caliper

10

Brake hose

11

Nuts

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

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

AS00.00-Z-0002-01A

 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 self-locking nuts and bolts

AH00.00-N-0001-01A

Topical note

Notes on evaluating brake disks

AH42.10-N-9406-07B

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

Clean area surrounding cap of brake fluid reservoir

Assembly cleaner

*BR00.45-Z-1028-04A

2

Remove cap from brake fluid reservoir and extract some brake fluid

 This prevents any overflowing of the brake fluid reservoir when pushing back the piston.

3

Remove corresponding wheel and tire assembly from rear axle

AR40.10-D-1100F

4

Release and disconnect brake pad wear sensor (6) from electric line of wear indicator

5

Unscrew screws (5) and remove brake caliper (4)

 Counterhold nuts (11) when removing bolts (5) from brake caliper (4).

6

Secure brake caliper (4) with attached brake hose (10) against falling down

7

Remove retaining springs (3)

8

Remove brake pads (2) from brake caliper support (1)

9

Push back brake pistons

AR42.10-D-1600-09F

 Resetting device

*000589524300

10

Check brake disk and brake pads (2) for wear

AR42.10-D-1600-11F

Brake lining wear limit

*BE42.10-N-1001-10A

Brake disk thickness

*BE42.10-N-1001-09B

 Brake caliper brush

*000589266800

 Caliper gauge

*140589001900

If a problem arises



Replace brake disk and brake pads (2).

AR42.10-D-0240FB

11

Clean contact surfaces of brakepads (2) on brake caliper (4) and on brake pistons

Assembly cleaner

*BR00.45-Z-1028-04A

 Brake caliper brush

*000589266800



Install

12

Apply light coating of brake paste to brakepads (2) on guide and piston contact surfaces of carrier plate

 Only sets of brake pads (2) approved by Mercedes-Benz may be installed.

Brake paste, Varybond

*BR00.45-Z-1072-06A

13

Install brake pads (2) in brake caliper support (1)

14

Install retaining springs (3)

15

Route electric line of brakepad wear sensor (6) through opening of brake caliper (4)


Do not allow electrical line to get caught in moving parts.
Otherwise false alarms about brakepad wear may occur.

16

Position brake caliper (4) on brake caliper support (1) and tighten new screws/bolts (5)


Do not twist brake hose (10) when installing.
Otherwise, the brake hose (10) will be damaged.

 Guide pin/catch bolt, top section of brake caliper to brake caliper support

*BA42.10-N-1002-12A

17

Plug brakepad wear sensor (6) onto electric line of wear indicator until it latches into place

18

Remove wheel and tire assemblies from rear axle

AR40.10-D-1100F

19

Check brake system for leaks

AR42.10-D-0100-01F

20

Check brake fluid level in expansion reservoir, if necessary



AP42.50-D-4210F

Check values for rear axle brake disks

Number

Designation

Model 909.64

Model 909.8

BE42.10-N-1001-09B

Brake disk thickness

New

mm

22

22

Wear limit

mm

19

19

Max. lateral runout

mm

0,1

0,1

Max. axial runout

mm

0,02

0,02

Repair limit dimension

mm

-

-

Test and adjustment values for service brake

Number

Designation

Model 909

BE42.10-N-1001-10A

Brake lining wear limit

mm

2

 Rear axle brake caliper

Number

Designation

Model 909.64

Model 909.8

BA42.10-N-1002-12A

Guide pin/catch bolt, top section of brake caliper to brake caliper support

M8

Nm

25

25

M81

Nm

-

-

M10 10.9

Nm

-

-

M101.25

Nm

-

-

Repair materials

Number

Designation

Order number

BR00.45-Z-1028-04A

Assembly cleaner

A 000 986 56 01

BR00.45-Z-1072-06A

Brake paste, Varybond

A 001 989 94 51