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

Model 463 

as of model year 2019 

Fig 1: Master Brake Cylinder Components Location - Model 463 As Of Model Year 2019

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
	Notes on externally invisible brake fluid loss		AH42.10-P-9406-02A
	Notes on self-locking nuts and bolts		AH00.00-N-0001-01A
	Brake fluid notes		AH42.50-P-0001-01A
	Notes on repairs to brake system		AH42.00-P-0003-01A
	Remove/install
1	Reduce vacuum in brake booster (5) by depressing brake pedal several times.
2	Remove brake fluid reservoir.		AR42.10-P-0301XG
3	Clean master brake cylinder (1) in the area of the connections of the brake lines (2, 3).	Thoroughly clean area around connecting points before opening brake system. Otherwise minute dirt particles in the hydraulic components 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.
4	Mark brake lines (2, 3) with corresponding connections.
5	Remove brake lines (2, 3) from master brake cylinder (1) and seal openings using suitable stop plugs.	Seal connection fittings at master brake cylinder (1). Otherwise the master brake cylinder (1) becomes damaged by the ingress of foreign objects.
		Record plug	Fig 2
6	Unscrew nuts (4).	Replace nuts (4).
		Model 463 (except 463.236/248/342) as of model year 2019 Nut, brake master cylinder to brake booster	*BA42.10-P-1001-05B
7	Guide master brake cylinder (1) out of brake booster (5) and then remove toward rear.	Collect the brake fluid which runs out using 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 brake booster (5). Otherwise the push rod is pushed out of its axial position. Replace seal between master brake cylinder (1) and brake booster (5).
8	Bleed brake system.		AR42.10-P-0010XG
	Check
9	Check brake system for leak tightness.		AR42.10-P-0100-01V
10	Perform brake test on test stand.

MASTER BRAKE CYLINDER

Number	Designation		Model 460, 461, 463 (except 463.236/248) up to model year 2019	Model 463 as of model year 2019
BA42.10-P-1001-05B	Nut, brake master cylinder to brake booster	Nm	25	23

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

Courtesy of MERCEDES-BENZ USA