Remove/check/install front axle brake pads

AR42.10-P-1600AC

Remove/check/install front axle brake pads

4.5.11

17.3.11

Perform brake test on dynamometer, added

Step 15

 

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



Notes on self-locking nuts and bolts

AH00.00-N-0001-01A



Brake fluid notes

AH42.50-P-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

Model 171

AP40.10-P-4050V

Model 209

AP40.10-P-4050Z



Checking

3

Check brake pad thickness and brake disks

 Only replace brake pads (43) and brake disks in complete sets if necessary.

Check brake lining thickness

AP42.10-P-4253A

Inspect condition of brake disks

Model 171

AP42.10-P-4258V

Model 209

AP42.10-P-4258BQ

 

Remove/install

4

Detach right front brake pad contact sensor from right front brake pad contact sensor connector

 Removal on left side is the same as on the right side.

 Model 209 with code P98 Black Series has a brake wear indicator on the right-hand side only.



Notes on installing brake wear indicator contact sensors

AH42.10-P-0003-01A

5

Unscrew right front brake pad contact sensor connector from brake caliper (31a)

 Removal on left side is the same as on the right side.

 Model 209 with code P98 Black Series has a brake wear indicator on the right-hand side only.

 Installation: Replace the self-locking bolt securing the contact sensor connector.

 Model 171

*BA42.10-P-1004-10P

 Model 209

*BA42.10-P-1003-10C

6

Remove bolt (30) and remove support of retaining spring (33)

 Model 171

*BA42.10-P-1005-10P

 Model 209

*BA42.10-P-1005-10C

7

Drive out retaining pins (41) using punch and remove retaining spring (31d)

 Installation: Knock retaining pins (41) all the way in. Ensure that retaining spring (31d) is correctly seated.

8

Pull brake pads (43) out of brake caliper (31a)

 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. The marking on the brake pads (43) must point in the direction of rotation of the wheel during forward travel.

9

Press back piston using pusher tool

On 6-piston fixed calipers on the front axle, secure pairs of opposing pistons with  wedges to prevent them from sliding out. Press back remaining pairs using  pusher tool.



*000589524300



*601589076300

If the pistons are difficult to move: 

Install new front axle brake caliper.

AR42.10-P-0070AC



Checking

10

Check brake caliper (31a) for leaks and dust boot for damage

 Replace dust boot or brake caliper (31a) if necessary.

AR42.10-P-0070AC



Clean

11

Clean contact surfaces of brake pads (43) in brake caliper (31a)

 Do not use any sharp-edged or pointed tools for cleaning to prevent damage.

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 (43) contact the brake disks

 Firm resistance should be noticeable at the brake pedal.



Checking

14

Check brake fluid level, correct if necessary

Brake system - inspect fluid level

Model 171

AP42.10-P-4210V

Model 209

AP42.10-P-4210Z

15

Carry out brake test on the test stand

AP42.00-P-4290BA

Number

Designation

Model
171

BA42.10-P-1004-10P

Self-locking bolt, brake pad contact sensor to brake caliper

Nm

7

BA42.10-P-1005-10P

Bolt for anti-rattle spring support

Nm

30

Number

Designation

Model
209
209.377
except with code P98

Model 209.377 with code P98

BA42.10-P-1003-10C

Self-locking bolt, brake pad contact sensor to brake caliper

Nm

8

8

BA42.10-P-1005-10C

Bolt for anti-rattle spring support

Nm

30

30