Brake Pad: Service and Repair

Removing And Installing Brake Pads On Fixed Caliper

Front Axle:

Rear Axle:

Remove/Install

DANGER:
- Risk of poisoning from swallowing brake fluid. Risk of injury from skin and eye contact with brake fluid.
- Pour brake fluid only into suitable and appropriately marked containers. Wear protective clothing and eye protection when handling brake fluid.

1 Remove wheels

Inspecting
2 Check brake pads and brake disks

CAUTION: If the brake pads are worn down beyond the permissible wear limit, the web between sealing groove and dust cap may be damaged, for this reason, check braking system for leaks using pressure gauge

3 Check fixed caliper (31a, 31b) for leaks and dust seal for damage

NOTE: If the fixed caliper is leaking or the dust seal is damaged then replace fixed caliper on front axle and replace fixed caliper on rear axle.

Remove/Install
4 Separate left front brake pad contact sensor connector (S10/1x1) and right rear brake pad contact sensor connector (S10/4x1) and pull out brake pad.

NOTE: Right and left side

CAUTION: See notes on installing brake pad wear contact sensors.

5 Drive out retaining pins (41) using a suitable drift punch (035)

NOTE: Installation: Drive in retaining pins as far as the stop using a suitable drift.

6.1 Pull brake pads (43) out of fixed brake caliper (31a, 31b)
- With brake pads that move easily.

6.2 If necessary, with seized brake pads use the pressing out lever (043) to press out the brake pads.

CAUTION:
- When pressing out the brake pads, insert a suitable wooden or plastic wedge between the lever and the fixed caliper.
- Installation: Do not use sharp or pointed implements to clean the brake pad guides. Install front axle brake pads (43) with niro panel (43a) dry. The marking (see arrow) on the niro panel (43a) must point in the running direction of the relevant wheel.
- Only sets of brake pads approved by Mercedes-Benz may be installed.
- Dispose of brake pads as special waste.
- Please ask local authorities if it is permitted to dispose of these parts as household-like industrial refuse.

7 Press back piston using resetting device (031)

CAUTION: Draw off some brake fluid beforehand if necessary, to prevent the brake fluid reservoir overflowing when pressing back the piston.

NOTE:
- On 4-piston fixed calipers on the front axle, secure one pair of opposing pistons with wedges to prevent them from sliding out. Then press back the other pair of pistons using the resetting device.
- If the piston is difficult to move then replace fixed caliper on front axle and replace fixed caliper on rear axle.

8 If necessary, clean the perforation in the brake disks

NOTE: Use a corresponding 4.3 mm dia. drift punch or drill for cleaning.

CAUTION: See notes on repairs to brake system

9 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 commissioning the vehicle, operate the brake pedal several times until the pressure in the brake system is built up and maintained.

10 Operate brake pedal several times until brake pads contact brake discs (firm resistance detectable).
11 Check brake fluid in brake fluid reservoir and correct if necessary.

NOTE: Fill brake fluid to max. mark on brake fluid reservoir or suction off if necessary.

CAUTION: See notes on handling brake fluid