Remove/check/install front axle brake pads - AR42.10-P-1600VA

MODEL 171.456

Fig 1: Identifying Front Axle Brake Pads Components

Courtesy of MERCEDES-BENZ USA

	Remove/install
	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.	-
	Risk of injury to skin and eyes caused by handling hot or glowing objects.	Wear safety gloves, protective clothing and safety glasses, if necessary.	-
	Notes on repairs to brake system		AH42.00-P-0003-01A
	Brake fluid notes		AH42.50-P-0001-01A
1	Open engine hood and raise to vertical position		AR88.40-P-1000V
2	Unscrew the cap on the brake fluid expansion reservoir and suction off some brake fluid	In order to prevent the expansion reservoir overflowing when the brake pistons (47) are pushed back.
3	Remove the front wheels
	Remove/install wheels, rotate if necessary		AP40.10-P-4050V
	Checking
4	Check brake pad thickness and brake disks (61)	Replace brake pads (43) and brake disks (61) in sets if necessary.
	Inspect condition of brake disks		AP42.10-P-4258V
	Check brake lining thickness	If the brake pads (43) are worn beyond the wear limit the web between the sealing groove and boot (47a) may be damaged, therefore: ↓	AP42.10-P-4253A
		Check brake system for leaks with pressure tester.	AR42.10-P-0015V
5	Disconnect electrical connector of right front brake pad contact sensor (S10/2) and pull right front brake pad contact sensor (S10/2) out of brake pad (43)	Installation: Replace defective right front brake pad contact sensor (S10/2).
	Notes on installing brake pad wear sensor contact sensors		AH42.10-P-0003-01A
6	Using punch hammer out retaining pins (41) and remove retaining springs (42d)	Installation: Hammer in retaining pins (41) as far as the stop.
7	Pull brake pads (43) out of brake caliper (31)	Press out seized brake pads (43) using lever (01). 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. Install brake pads (43) with plate (43a).
			Fig 2
	Checking
8	Check brake caliper (31) and boots (47a)	In the event of leakage or damage: ↓
		Replace brake caliper (31).	AR42.10-P-0070VA
9	Press back brake piston (47) using resetting device (02)	Secure the second pair of pistons of the brake caliper (31) beforehand with wedges to prevent them from falling out. If the brake pads (43) of several brake calipers (31) are removed, also secure their brake pistons (47) to prevent them from falling out. Do not fit the resetting device (02) to the brake disk (61), but push back the opposite brake pistons (47) simultaneously. If brake pistons (47) are sluggish: ↓
		Replace brake caliper (31).	AR42.10-P-0070VA
			Figure
			Figure
	Clean
10	If necessary, clean the perforation of brake disks		-
11	Clean the contact surfaces of the brake pads (43) in the brake caliper (31) with rags	Do not damage boots (47a). Do not use any sharp-edged or pointed tools in order to avoid damage.
		LU cleaner	*BR00.45-Z-1028-04A
12	Install in the reverse order
	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.	-
13	Press the brake pedal several times until the brake pads (43) contact the brake disks (61)	A firm resistance must be noticeable at the brake pedal.
	Checking
14	Inspect fluid level in expansion reservoir, adjust to correct level if necessary
	Brake system - inspect fluid level		AP42.10-P-4210V
15	Perform a function test
	Brake testing on test stand		AP42.00-P-4290V