Remove/Install Master Brake Cylinder - AR42.10-S-0300E

Model 447, 448

Fig 1: Master Brake Cylinder Components Location - Model 447 (Shown On Model 447.### 1# With Engine 622)

Courtesy of MERCEDES-BENZ USA

Shown on model 447.### 1# with engine 622

	Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)	Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines. Model 447 with engine 780	AS00.00-Z-0035-01A
	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 the engine, actuate brake pedal several times until pressure is built up and maintained in the brake system.	AS42.50-Z-0002-01A
	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	Information on preventing damage to electronic components due to electrostatic discharge		AH54.00-P-0001-01A
Notice	General information on vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system as well as personal protective equipment	Model 447 with engine 780	AH00.00-Z-0300-01A
Notice	Notes on externally invisible brake fluid loss		AH42.10-P-9406-02A
Notice	Brake fluid notes		AH42.50-P-0001-01A
Notice	Notes on repairs to brake system		AH42.00-P-0003-01A
	Note on calculation of tightening torque when using insertion or socket tools with various effective lengths		AH00.00-P-0015-01CW
	Notes on inspecting corrosion on brake lines		AH42.50-Z-0002-01A
	Remove/install
1	Switch off ignition and store transmitter key outside of transmission range (min. 2 m).
2	Remove vacuum in brake booster.	To do this, operate brake pedal several times.
3	Remove intake manifold pressure sensor.	Model 447.### 1# with engine 654.9	AR07.04-S-0102E
4	Suction off brake fluid from brake fluid reservoir (2) and then reseal brake fluid reservoir (2).	Commercially available devices/tools Extraction bellows
5	Detach feed line (4) of clutch master cylinder from brake fluid reservoir (2).	Model 447 with transmission 700.7, 710.5, 711.6 Catch escaping brake fluid using a suitable rag and seal openings. Record plug	Fig 6
6	Disconnect electrical connector (3).
7	Remove expansion rivet (5).	Check expansion rivet (5) for damage. If damage is found, ↓ replace expansion rivet (5).
8	Detach brake fluid reservoir (2) from air/water duct and swivel out of working area.
9	Unscrew retaining screws (6) and remove brake lines from master brake cylinder (1).	Catch escaping brake fluid using a suitable rag and seal openings. Different retaining screws (6) are installed depending on the vehicle version. Retaining screw, brake line to master brake cylinder	*BA42.10-Z-1004-04KOD
		Box wrench bit	Fig 5
		Box wrench	Fig 2
		Box wrench bit	Fig 4
		Record plug	Fig 6
10	Loosen retaining screws (7) of brake lines on hydraulic unit.	Only loosen brake lines enough for the master brake cylinder (1) to be guided past the brake lines. Different retaining screws (7) are installed depending on the vehicle version. Collect any escaping brake fluid using suitable rags. Retaining screw, brake line to hydraulic unit	*BA42.10-Z-1003-04KOD
		Box wrench bit	Fig 5
		Box wrench	Fig 2
		Box wrench bit	Fig 4
11	Detach nuts (8) and remove master brake cylinder (1) with brake fluid reservoir (2).	Replace the sealing ring (9) on the master brake cylinder (1). Nut, brake master cylinder to brake booster	*BA42.10-Z-1001-05KOE
		Assembly tool	Fig 3
12	Detach brake fluid reservoir (2) from master brake cylinder (1).	When replacing the master brake cylinder (1).
13	Install in the reverse order.
14	Bleed brake system.		AR42.10-S-0010E
	Check
	Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.	Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts. Model 447 with engine 254, 274, 622, 651, 654 Model 448	AS00.00-Z-0005-01A
15	Check brake system in area of master brake cylinder (1), hydraulic unit and brake fluid reservoir (2) for leak tightness.		AR42.10-S-0100-01E