Remove/Install Master Brake Cylinder - AR42.10-P-0300LWO

Model 238 

Fig 1: Master Brake Cylinder Components Location - Model 238

Courtesy of MERCEDES-BENZ USA

	Risk of poisoning  from swallowing brake fluid. Risk of injury  from skin and eye contact with brake fluid	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
Notice	Notes on externally invisible brake fluid loss		AH42.10-P-9406-02A
Notice	Notes on repairs to brake system		AH42.00-P-0003-01A
Notice	Brake fluid notes		AH42.50-P-0001-01A
	Remove/install
1	Reduce vacuum in BAS brake booster (A7/7) by depressing brake pedal several times
2	Remove brake fluid reservoir		AR42.10-P-0301LWO
3	Clean master brake cylinder (1) in area of brake line (2) connections	Before opening the brake system, the area around the separation points should be cleaned thoroughly. Otherwise minute particles of dirt in the hydraulic components can result in malfunctions and total failure of the brake system. Use clean, lint-free rag only. Do not use any compressed air for cleaning when the brake system is open. Assembly cleaner	*BR00.45-Z-1028-04A
4	Remove brake lines (2) from master brake cylinder (1)	Retaining screw, brake line to master brake cylinder	*BA42.10-P-1003-04P
		Torque tool set	Fig 3
5	Seal connection fittings on master brake cylinder (1) and brake lines (2)	Record plug	Fig 2
6	Unscrew nut (3) and nut (arrow)
Notice	Notes on self-locking nuts and bolts	: Replace nut (3) and nut (arrow).	AH00.00-P-0001-01KOA
		Nut, brake master cylinder to brake booster	*BA42.10-P-1001-05L
		Torque tool set	Fig 3
7	Guide master brake cylinder (1) out under the strut (4) out of BAS brake booster (A7/7) and remove toward the back	Collect brake fluid which runs out with an absorbent rag. Otherwise the vehicle paint can be damaged.
		Do not tilt the master brake cylinder (1); pull it forward and in a straight line out of the BAS brake booster (A7/7). The push rod will otherwise be pressed out of its axial position. : Replace seal between master brake cylinder (1) and BAS brake booster (A7/7).
8	Install in the reverse order
9	Bleed brake system		AR42.10-P-0010LWE
	Check
10	Carry out brake test on the test stand
			AP42.00-P-4290BA

MASTER BRAKE CYLINDER

Number	Designation		Model 238
BA42.10-P-1001-05L	Nut, brake master cylinder to brake booster	Nm	25

BRAKE LINES, BRAKE HOSES

Number	Designation		Model 238
BA42.10-P-1003-04P	Retaining screw, brake line to master brake cylinder	Nm	16

Fig 2: Identifying Record Plug (129 589 00 91 00)

Courtesy of MERCEDES-BENZ USA

Fig 3: Identifying Torque Tool Set (003 589 05 09 00)

Courtesy of MERCEDES-BENZ USA

REPAIR MATERIALS

Number	Designation	Order number
BR00.45-Z-1028-04A	Assembly cleaner	A 000 986 56 01