Removing, checking and installing rear axle brake pads - AR42.10-P-1700RA

MODEL 211.076 /077 /276 /277

MODEL 230.472 /474 /476 /477 /479

Fig 1: Identifying Rear Axle Brake Pads Components

Courtesy of MERCEDES-BENZ USA

	Remove/install
	Risk of injury caused by body parts being jammed or crushed. Risk of injury to skin and eyes caused by brake fluid spraying out at high pressure when working on the SBC brake system	Deactivate SBC brake system using STAR DIAGNOSIS.	AS42.46-Z-0001-01A
	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
	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.
			*BA42.50-P-1001-01D
2	Deactivate SBC brake system using STAR DIAGNOSIS.	Vehicles with Sensotronic Brake Control (SBC)
		The following steps should be run through in STAR DIAGNOSIS:
		Select menu item "SBC-Sensotronic Brake Control"/"Deactivate 'SBC' system".
		Then process all the individual steps from top to bottom.
3	Remove rear wheels.
	Remove/install wheels, rotate if necessary		AP40.10-P-4050Z
4	Remove brake pad contact sensor (S10/4)	Installation: Replace defective contact sensor (S10/4).
	Notes on installing brake pad wear sensor contact sensors		AH42.10-P-0003-01A
5	Detach brake pad contact sensor connector (S10/4x1) from fixed brake caliper (31)		*BA42.10-P-1002-12H
			*BA42.10-P-1002-12B
6	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.
7	Pull brake pads (31g) out of fixed brake caliper (31)	In order to prevent damage when pressing out the brake pads (31g) insert wedge between the lever and fixed brake caliper (31) .
		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) with retaining spring (31d) ungreased. The marking on the retaining spring (31d) must point in the direction of rotation of the wheel when driving forwards.
			Figure
			Figure
	Checking
8	Check brake lining thickness and brake disks	Only replace brake pads (31g) and brake disks in complete sets if necessary.
	Check brake lining thickness		AP42.10-P-4253A
	Inspect condition of brake disks		AP42.10-P-4258R
9	Check fixed caliper (31) for leaktightness and dust boots of brake pistons for damage and correct seating	If the fixed brake caliper (31) is leaking or the dust boot is damaged or incorrectly seated: ↓
		Install new fixed brake caliper (31).	AR42.10-P-0080RA
10	Press back brake piston using pusher tool	In each case secure an opposed pair of brake pistons beforehand with wedges to prevent l them from being pressed out. If the brake pads (31g) of several brake calipers are removed, also secure their brake pistons to prevent them from falling out.
		Do not fit pusher tool on the brake disk but push back the opposite brake pistons simultaneously. If brake pistons are sluggish: ↓
		Install new fixed brake caliper (31).	AR42.10-P-0080RA
			Figure
11	Install in the reverse order
	Clean
12	If necessary, clean the perforation of brake disks		AR42.10-P-2260-01I
13	Clean contact surfaces of brake pads (31g)	Do not use any sharp-edged or pointed tools to prevent damage.
14.1	Activate SBC brake system using STAR DIAGNOSIS	Vehicles with Sensotronic Brake Control (SBC)
		The following steps should be run through in STAR DIAGNOSIS:
		Select the menu item "SBC-Sensotronic Brake Control"/"Initial startup after repair"/"Remove/install brake pads".
		Then process all the individual steps from top to bottom.
	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
14.2	Operate the brake pedal several times until the brake pads (31g) contact the brake disks	Vehicles with Adaptive Brake (ABR)
		Firm resistance should be noticeable at the brake pedal.
15	Inspect fluid level in expansion reservoir, adjust to correct level if necessary
	Brake system - inspect fluid level		AP42.10-P-4210Z