Water Pump: Service and Repair

11 51 000 Removing and installing/replacing coolant pump (N55)





Warning!
Risk of scalding!
Only perform this work after engine has cooled down.





Important!
If a coolant pump that has already been operated is reused, it must be filled with coolant after removal.
Mixture ratio, water: coolant = 1 : 1
Protect plug connections against coolant and contamination.





Recycling:
Catch and dispose of drained coolant in a suitable container.

Observe country-specific waste disposal regulations.





Necessary preliminary work:
^ Follow diagnosis instructions.
^ Remove engine splash guard.
^ Remove charge air cooler.
^ Drain coolant.
^ Remove thermostat.
^ Remove reinforcement plate (E70,E71 only).





Disconnect plug connection (1).

Release coolant hose (2).

Installation Note:
Note installation hose clamps.

Tightening torque 11 53 9AZ.





Release coolant hose (1).

Installation Note:

Note installation hose clamps.

Tightening torque 11 53 5AZ.





Follow assembly instructions:

Installation Note:
Hose clamps (1) must be installed in the center of the marked area (see graphic).





Release screws (1).

Tightening torque 11 51 2AZ.

Installation Note:
Replace aluminum screws.





Unclip cable (1) from bracket.

Release screw (2).

Tightening torque 11 51 2AZ.





Installation Note:
If the electric coolant pump is reused, it must be rotated one turn due to the breakaway torque at the impellers.

Assemble engine.

Bleeding instructions must be observed without fail.