Replacement of brake fluid A. Vehicles w/o ASR, B. Vehicles w/ ASR, I, C. Vehicles w/ ASR II and ASR III - wh4280pkw0000x(4280)

Model 107 from 8/85; 123; 124, 129, 140 up to 6/93; 126 from 9/85; 201 from 1/85 

1. Vehicles without ASR 
   Fig 1: Identifying Brake Fluid Supply Reservoir Cap

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   Fig 2: Locating Hole On Reservoir Cap

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   HANDLE BRAKE FLUID WITH CARE (4280/5)
   
   

   Fluid level in brake fluid supply reservoir	note.
   Cap (11)	screw off, screw on.
   Vent hole (arrow)	in cap, check for clogging (vehicles up to 09/90).
   Brake fluid supply reservoir	drain chambers down to fluid level of approx. 10 mm.
   NOTE: If completely emptied the entire brake system must be bled (see Repair Instructions).

   WITH FILLING AND BLEEDING UNIT
   
   

   Filling and bleeding unit

   connect according to manufacturer's instructions. Allow approx. 80 cm 3 of brake fluid to flow out at each wheel brake and, where applicable, at the clutch slave cylinder.

   WITHOUT FILLING AND BLEEDING UNIT
   
   

   Expansion reservoir (10)	fill up to "MAX" mark with brake fluid. Pump old brake fluid out at each fixed caliper and, where applicable, at clutch slave cylinder with 10 pump strokes at each point. Refill with new brake fluid.
   NOTE: When correcting the brake fluid level ensure that the original fluid level is not exceeded to prevent the brake fluid supply reservoir from overflowing when the brake pads are replaced.
   Clear, bubble-free brake fluid should flow out through the bleed hose under all circumstances regardless of the replacement method used.

   BRAKE FLUID
   
   

   Use only approved brake fluid

   see Specifications for Service Products sheet 331.0

2. Vehicles with ASR, 1st version 
   Fig 3: Identifying Brake Fluid Supply Reservoir

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   Fig 4: Identifying Bleed Screw

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
   HANDLE BRAKE FLUID WITH CARE (4280/5)
   
   

   Fluid level in brake fluid supply reservoir	note.
   Pressure reservoir	bleed at bleed screw (SP3) with ignition switched off.
   Cap	screw off, screw on.
   Vent hole	in cap, check for clogging (vehicles up to 09/90).
   Brake fluid supply reservoir	drain chambers down to fluid level of approx. 10 mm.
   NOTE: If completely emptied the entire brake system must be bled (ASR vehicles with 500 cm 3 of brake fluid per wheel, see Repair Instructions).
   Filling and bleeding unit	connect according to manufacturer's instructions.
   At each wheel brake allow	approx. 80 cm 3  of brake fluid to flow out.
   Bleed screw (1)	open until clear, bubble-free brake fluid flows out.
   Engine	start.
   Bleed screw (SP3)	open until clear, bubble-free brake fluid flows out, close.
   NOTE: If the bleeding procedure on bleed screw "SP3" lasts too long with engine running, the charging pump switches off (fluid no longer flows out through bleed hose, "ASR" indicator lamp comes on). In this case shut off engine and start again, continue bleeding procedure.
   Engine	shut off.
   Filling and bleeding unit	disconnect and correct brake fluid level in brake fluid supply reservoir.
   NOTE: When correcting the brake fluid level ensure that the original fluid level is not exceeded to prevent the brake fluid supply reservoir from overflowing when the brake pads are replaced.

   BRAKE FLUID
   
   

   Use only approved brake fluid

   see Specifications for Service Products sheet 331.0

3. Vehicles with ASR II and ASR III 

Fig 5: Identifying Charge Pump And Bleed Screw

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Handle brake fluid with care. 

1. a) Fill brake fluid only into containers which make any accidental consumption of the brake fluid impossible.

   (Fatal dose approx. 100 cc) 

2. b) Even minimum quantities of mineral oil lead to failure of the brake system, because the rubber parts decompose.

   If mineral oil is found or suspected of being present in the brake system, proceed as follows:

   1. Replace tandem master brake cylinder and brake fluid supply reservoir.
   2. Thoroughly flush entire brake system with new brake fluid.
   3. Replace all brake parts with rubber components such as brake calipers, brake hoses, ABS or ASR hydraulic unit, ASR pressure accumulator and charge pump, which may have come into contact with the mineral oil.
   4. Bleed brake system.
3. c) Do not allow brake fluid to come into contact with the vehicle paint, because it contains constituents which act as a solvent for the paint.
4. d) Brake fluid is highly hygroscopic, meaning that it absorbs moisture from the air reducing its boiling point. For this reason brake fluid should only be stored in well-sealed storage containers.
5. e) Never reuse brake fluid pumped out while bleeding, because it may contain foreign particles and/or water, which would contaminate the brake system.
6. f) Dispose of used brake fluid as special waste.

   (Disposal instructions in MBVD environmental protection catalog chapter 2.6 - pages 2 - 43).

   Brake fluid which is not contaminated with oil can be recycled.

   This requires separate collection and storage of the brake fluid.

   For this purpose we recommend the collecting system from the Schroder company which is described in the MBVD workshop equipment catalog under the following numbers:

   0210 2200 E 07 05 Collection tank

   0210 2200 E 07 01 Receiving tank

   0210 2200 E 07 02 Hand pump

   0210 2200 E 07 03 Transport rack

   The same description is given in the Service Products Manual, Volume 2, Chapter U, Group 00 (22).