Filling and bleeding the power steering pump/tandem pump - RA46097650715X(46-0715)

1. Version (model 201 up to 09/84) 

   When engine is cold (room temperature approx. 20°C) oil level 6-8 mm below marking (arrow). When oil is at operating temperature (approx. 80°C) correct oil level up to the embossed or cast-in marking (arrow).

   Fig 1: Identifying Power Steering Pump/Tandem Pump Oil Level (Version (Model 201 Up To 09/84))

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
2. Version 10/84 to 01/91 

   The reservoir is filled correctly when the oil (20-50°C) is between the min. and max. markings, 28-36 mm below the edge of the reservoir.

   Fig 2: Identifying Power Steering Pump/Tandem Pump Oil Level (Version 10/84 To 01/91)

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
3. Version as of 02/91 

   When engine is cold (room temperature 20°C) oil level at the maximum marking of the oil level display (30c) of the power steering/tandem pump (30).

   Fig 3: Identifying Power Steering Pump/Tandem Pump Oil Level (Version As Of 02/91)

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

   Engine 120 

   Remove plastic cover (30e).

   Fig 4: Identifying Plastic Cover (30e)

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

   The oil dipstick with "min" and "max" marking for the oil level check is on the cap of the expansion reservoir.

   Fig 5: Identifying Power Steering Pump/Tandem Pump Oil Level (Engine 120)

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
4. Filling/bleeding 

   Before starting the engine, fill with specified steering gear oil to approx. 10 mm below the upper edge of the reservoir.

   Start engine, allow to run for approx. 1 s. Switch off engine and immediately replenish extracted oil. The power steering pump must not  ingest any air. Turn steering several times anticlockwise and clockwise towards full lock so that the system can bleed itself. On vehicles with tandem pump (level control, ADS, ASD or 4MATIC) bleed the respective systems separately.

5. Oil level check 

   Correct oil level depending on the version.

6. Leak testing 

   A power steering/tandem pump must only be replaced if oil leakage (pronounced formation of droplets) has been established and the oil level is below the minimum marking.

   A slight oil film on the radial seal ring or on the housing joint face is due to the system.

   1. Leakage at the pipe connections:

      Retighten high pressure hose. If this is not successful, the connection nipple must be checked for damage. If necessary, replace high-pressure hose.

   2. Formation of droplets on the underside of the power steering pump:

The cause of this is often an overfilled reservoir.