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

Model 172, 204

MODIFICATION NOTES

05.08.2010	"Perform Brake test on test bench" reference changed	Test sequence augmented/revised
06.04.2017	Retaining Screw, Brake line to master Brake cylinder		BA42.10-P-1003-04L

Fig 1: Master Brake Cylinder Components Location - Model 172 (Shown On Model 204)

Courtesy of MERCEDES-BENZ USA

Shown on Model 204

	Remove/install
	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
	Brake fluid notes		AH42.50-P-0001-01A
	Notes on repairs to Brake system		AH42.00-P-0003-01A
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 hood	Model 204
2.2	Open engine hood and raise to vertical position	Model 172	AR88.40-P-1000V
3	Unscrew Screw (1), remove expansion rivets (2) and remove support (3)	Model 204 Model 204.9: Two Screws (1) are installed.
4	Drain Brake fluid from Brake fluid expansion reservoir (4)
5	Disconnect electrical connector (5) from Brake fluid level switch (S11)
6	Detach feed hose (6) for clutch master cylinder from Brake fluid expansion reservoir (4)	Vehicles with manual transmission Seal feed hose (6). Record plug	Fig 2
7	Remove Screw/ Bolt (7)	Model 204
8	Detach Brake fluid expansion reservoir (4) from master Brake cylinder (8)	Model 204 Seal connections on master Brake cylinder (8). Otherwise, the master Brake cylinder (8) will be damaged by the ingress of foreign objects. : Replace seals (9). Record plug	Fig 2
9	Pull vacuum line (10) with check valve out of BAS Brake booster (A7/7)
10	Release piping from firewall and place to one side	Model 204.9
11	Remove vacuum line (10) from firewall	Model 204.9	AR43.10-P-0355CW
12	Remove torsion bar linkage from master Brake cylinder (8)	Model 172	AR42.10-P-0300-02V
13	Mark Brake lines (11) relative to corresponding connections
14	Detach Brake lines (11) from master Brake cylinder (8)	Seal line connections. Retaining Screw, Brake line to master Brake cylinder	*BA42.10-P-1003-04L
		Box wrench bit	Fig 3
		Record plug	Fig 2
15	Unscrew nuts (12) from BAS Brake booster (A7/7)	Nut, master Brake cylinder to Brake booster	*BA42.10-P-1001-05K
16	Remove master Brake cylinder (8)	Do not tilt master Brake cylinder (8), instead pull it straight forward out of BAS Brake booster (A7/7). Otherwise the push rod will be pressed out of its axial position. : Replace the sealing ring (13).
17	Pull out locking pin (7) and detach Brake fluid expansion reservoir (4) from master Brake cylinder (8)	Model 172 : When replacing master Brake cylinder (8). : Replace seals (9).
18	Install in the reverse order
19	Bleed Brake system		AR42.10-P-0010CW
	Check
20	Check Brake system for leaks		AR42.10-P-0100-01V
21	Carry out Brake test on the test stand
			AP42.00-P-4290BA