Remove/check/install front axle brake pads

AR42.10-P-1600CM

Remove/check/install front axle brake pads

7.2.08

 

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



Notes on self-locking nuts and bolts

AH00.00-N-0001-01A

1

Unscrew the cap on the brake fluid expansion reservoir and suction off some brake fluid

 In order to prevent the expansion reservoir overflowing when pressing back the brake pistons.

2

Remove the front wheels



Remove/install wheels, rotate if necessary

AP40.10-P-4050Z

3

Unhook spring (31d)

4

Remove brake pad contact sensor

 Installation: Replace defective contact sensors.



Notes on installing brake pad wear sensor contact sensors

AH42.10-P-0003-01A

5

Detach covers (31b) and remove guide pins (31c)

Model 170

*BA42.10-P-1003-10P

Model 208

*BA42.10-P-1003-10D

Model 210

*BA42.10-P-1003-10F

6

Remove floating brake caliper (31a) with inner brake pad

 Attach floating caliper (31a) to vehicle so that it is free of tension. Do not kink or tension brake hose, as otherwise it will be damaged.

7

Remove brake pads (31g)

 Brake pads (31g) 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 (31g) approved by Mercedes-Benz may be built-in as a set. Install brake pads (31g) without grease. Insert inner brake pad with riveted on spring arrow in brake piston, insert outer brake pad in brake caliper support (33).



Checking

8

Check brake pad thickness and brake disks

 Only replace brake pads (31g) and brake disks in complete sets if necessary.



Inspect condition of brake disks

AP42.10-P-4258AM



Check brake lining thickness

 If the brake pads (31g) have worn down to beyond the wear limit, the bar between the sealing groove and dust cap may be damaged; therefore: 

AP42.10-P-4253AM

Inspect brake system for leaks with pressure tester.

AR42.10-P-0015A

9

Check floating caliper (31a) for leaks and dust boot (47) for signs of damage and correct seating

 If floating brake caliper (31a) is leaky or dust boot (47) is damaged or not seated correctly:

Repair floating caliper:

Except model 170.466,
except model 208.370/470 as of 19.1.99 without code 491 USA version,
except model 210.270 as of 8.2.99,
except model 210.070 as of 8.2.99 without code 491 USA version,
without code 498 Japan version,
without code 625 Australia version

AR42.10-P-0152B

Model 170.466,
model 208.370/470 as of 19.1.99 without code 491 USA version,
model 210.270 as of 8.2.99,
model 210.070 as of 8.2.99 without
code 491 USA version,
without code 498 Japan version,
without code 625 Australia version

10

Press back brake piston using resetting device (031).

 If brake pads (31g) have been removed from several brake calipers, secure their brake pistons beforehand with wedges to prevent them from falling out. If the brake piston is difficult to move: 

Repair floating caliper:

Except model 170.466,
except model 208.370/470 as of 19.1.99 without code 491 USA version,
except model 210.270 as of 8.2.99,
except model 210.070 as of 8.2.99 without code 491 USA version,
without code 498 Japan version,
without code 625 Australia version

AR42.10-P-0152B

Model 170.466,
model 208.370/470 as of 19.1.99 without code 491 USA version,
model 210.270 as of 8.2.99,
model 210.070 as of 8.2.99 without
code 491 USA version,
without code 498 Japan version,
without code 625 Australia version

Resetting device

*000589524300

Wedge

*601589076300



Clean

11

Clean contact surfaces of brake pads (31g) at floating caliper (31a) and brake caliper support (33)

 Do not damage dust boot (47).

 Brake caliper brush

*000589266800

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

Operate the brake pedal several times until the brake pads (31g) contact the brake disks

 Firm resistance should be noticeable at the brake pedal.

14

Inspect fluid level in expansion reservoir, adjust to correct level if necessary



Brake system - inspect fluid level

AP42.10-P-4210Z

Number

Designation

Model
170

BA42.10-P-1003-10P

Guide pin, brake caliper to brake caliper support

Nm

25

Number

Designation

Model
208

BA42.10-P-1003-10D

Guide pin on caliper support

Nm

25

Number

Designation

Model
210

BA42.10-P-1003-10F

Guide pin on caliper support

Nm

25