Water Pump: Service and Repair

11 51 000 Removing and installing/replacing water pump (N52K)





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





Recycling:
Catch and dispose of drained coolant in a suitable container.
Observe country-specific waste-disposal regulations.





Important!
If a water pump that has already been operated is reused, it must be filled with coolant immediately after removal.

Mixture ratio, water: coolant = 1 : 1
Protect plug connections against coolant and contamination.
Cover plug connections with suitable materials.





Important!
Aluminium-magnesium materials.
No steel screws/bolts may be used due to the threat of electrochemical corrosion.
A magnesium crankcase requires aluminium screws/bolts exclusively.
Aluminium screws/bolts must be replaced each time they are released.
Aluminium screws/bolts are permitted with and without colour coding (blue).
For reliable identification:
Aluminium screws/bolts are not magnetic.
Jointing torque and angle of rotation must be observed without fail (risk of damage).





Necessary preliminary tasks:
^ Remove coolant thermostat
^ Remove front right cross strut ( E89 only )





Loosen hose clamps (1).

Remove coolant hose.

Tightening torque 11 53 5AZ.

Unfasten hose clip (2).

Remove coolant hose.

Tightening torque 11 53 3AZ.

Disconnect plug connection (4).

Release screws (3).

Tightening torque 11 53 1AZ.

Release screws (5).

Tightening torque 11 51 1AZ.

Installation:
Replace aluminium screws.

Installation:
If the electric water pump is reused, it must be rotated one turn due to the breakaway torque at the blade wheels.





Assemble engine.

Venting instructions must be observed without fail.

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