23 42 020Replacing electric motor on hydraulic pump (GS7S47BG SMG)

Before working on hydraulic system:
  • Reduce pressure in hydraulic system by means of Service Functions in DIS Tester (Replacement and Repair)
  • Disconnect battery negative lead.

After replacing electric motor on hydraulic pump:

Necessary preliminary tasks:

Disconnect connector (1).

Release cable tie (2).


Use high-temperature-resistant cable ties (approx. 140 °).

Release cable tie (1).

Release screw (2).

Tightening torque 23 41 26AZ.


Use high-temperature-resistant cable ties (approx. 140 °).

Unclip oxygen sensor plugs (1).

Release nut (2) and remove holder (3).

Unclip return line (1) from holder and place to one side.

Unlock and disconnect plug (2).


Risk of damage!

Adhere to conditions of absolute cleanliness when carrying out the following tasks.


Catch hydraulic fluid from expansion tank in a suitable container.

Release clamp (1).

Carefully detach reservoir in direction of arrow and secure or tie up to transmission with cable tie.

Do not detach return line from reservoir.


Replace clamp.

Replace sealing rings in expansion tank only if damaged.

Release screws (1) and remove hydraulic pump.Important!

Risk of damage:

Only the screws identified in the picture may be released. Failure to comply with this requirement will result in hydraulic pump malfunction!

  • Before installing pump, adhere to conditions of absolute cleanliness.
  • Align drive shaft (1) of electric motor horizontally
  • Check sealing ring (2) for damage. Sealing ring may only be replaced if damaged!

  • Attach greased coupling element (1) from repair kit to oil pump (2) and align horizontally to electric motor drive shaft.

    Note: Hydraulic pump is relatively difficult to turn because of the high pressure level.

  • Attach oil pump to electric motor drive shaft until it can be heard to snap into place.

    Tightening torque 23 41 30AZ

Release screws (1).

Tightening torque 23 41 24/ 26AZ


Do not replace screws.

Release screws (1).

Tightening torque 23 41 31AZ

  • Clean inside surface (1) of pump block with paper towel.
  • Check O-ring (2) for damage.

    O-ring may only be replaced if it is damaged!

  • Coat O-ring (2) with petroleum jelly before installing electric motor

Bend open retaining clip (1) a little.

Turn electric motor (2) in direction of arrow, slide towards rear and remove.

Installation:To facilitate installation, coat rubber sleeve on pressure accumulator with petroleum jelly.



Before modifying holder on electric motor:

Check installation location.

Mark holder (1) in relation to screws (2)

Release screws (2) and convert holder (1).

New electric motors are supplied with blind holes and new screws.

The blind holes have no threads - these are cut by the screws.

After completing work:
  • Top up fluid level in hydraulic system
  • Clear fault memory
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