Remove/install master brake cylinder - AR42.10-P-0300CW

WARNING: This page is about a different car, the 2011 Mercedes-Benz C300, 2010 Mercedes-Benz C300, 2009 Mercedes-Benz C300, and 2008 Mercedes-Benz C300. However, it is still accessible from the selected car via links, so may be relevant.

MODEL 204, 172

Shown on model 204

Fig 1: Identifying Master Brake Cylinder Remove/Install 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.	AS42.50-Z-0001-01A
	Brake fluid notes		AH42.50-P-0001-01A
	Notes on repairs to brake system		AH42.00-P-0003-01A
	Notes on externally invisible brake fluid loss		AH42.10-P-9406-02V
1	Eliminate vacuum in BAS brake booster (A7/7)	To do this, press the brake pedal several times with the engine switched off.
2.1	Open engine hood	Model 204
2.2	Open engine hood and raise to vertical position	Model 172	AR88.40-P-1000V
3	Unscrew bolt (1), remove expansion clips (2) and take out strut (3)	Model 204 Model 204.9: Two bolts (1) are installed.
4	Suction off brake fluid from the brake fluid reservoir (4)
5	Disconnect electrical connector (5) from brake fluid level switch (S11)
6	Pull feed hose (6) for clutch master cylinder off brake fluid expansion reservoir (4)	Vehicles with manual transmission
		Seal feed hose (6). Set of stop plugs	Fig 3
7	Unscrew bolt (7)	Model 204
8	Detach brake fluid expansion reservoir (4) from master brake cylinder (8)	Model 204 Seal the connections on the master brake cylinder (8). Foreign objects can otherwise enter the master brake cylinder (8) and cause damage. Set of stop plugs Installation: Replace seals (9).	Fig 3
9	Pull vacuum line (10) with check valve out of BAS brake booster (A7/7)
10	Detach rubber edge strip from splash wall and place to one side	Model 204.9
11	Remove vacuum line (10) from splash wall	Model 204.9	AR43.10-P-0355CW
12	Remove pendulum support from master brake cylinder (8)	Model 172	AR42.10-P-0300-02V
13	Label brake lines (11) according to connections
14	Detach brake lines (11) on master brake cylinder (8)	Seal line connections. Box wrench bit Set of stop plugs	*BA42.10-P-1003-04 Fig 2 Fig 3
15	Unscrew nuts (12) from BAS brake booster (A7/7).		*BA42.10-P-1001-05K
16	Take out master brake cylinder (8)	Do not tilt the master brake cylinder (8); pull it forward and in a straight line out of the BAS brake booster (A7/7). The push rod will otherwise be pushed out of its axial position. Installation: Install new sealing ring (13).
17	Pull out locking pin (7) and detach brake fluid expansion reservoir (4) from master brake cylinder (8)	Model 172 When installing a new master brake cylinder (8). Installation: Replace seals (9).
18	Install in the reverse order
19	Bleed brake system		AR42.10-P-0010CW
	Checking
20	Check brake system for leaks		AR42.10-P-0100-01V
21	Carry out brake test on the test stand		AP42.00-P-4290BA

MASTER BRAKE CYLINDER

Number	Designation		Model 172	Model 204
BA42.10-P-1001-05K	Nut, brake master cylinder to brake booster	Nm	25	25

BRAKE LINES, BRAKE HOSES

Number	Designation			Model 172	Model 204
BA42.10-P-1003-04L	Union nut, brake line to master brake cylinder	Ø4.75	Nm	18	18
		Ø6	Nm	18	18
		Ø8	Nm	24	24

Fig 2: Identifying Box Wrench Bit (000 589 75 03 00)

Courtesy of MERCEDES-BENZ USA

Fig 3: Identifying Set Of Stop Plugs (129 589 00 91 00)

Courtesy of MERCEDES-BENZ USA