Water Pump: Service and Repair

11 51 000 Removing and installing/replacing coolant pump (N63)





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 coolant pump which has already been operated is reused, it must be filled immediately after being removed with coolant (mixture ratio 1:1 / water: coolant).








Necessary preliminary tasks:
^ Drain coolant
^ Remove intercooler expansion tank
^ Remove alternator drive belt





Important!
Risk of damage!
Coolant emerges when the coolant hoses are detached from the coolant thermostat and coolant pump.
Cover surrounding components and plug connections with suitable apparatus

Note:
For purposes of clarity, the graphic shows the supplementary coolant pump removed.

Remove plug connections (2 and 3).

Installation:
Plug connections (2 and 3) must snap audibly into place!

Unlock quick-release coupling on coolant hose (1).

Detach coolant hose (1) and lay to one side.





Release screw (4).

Tightening torque 11 51 3AZ.

Detach pipe (3) and lay to one side.

Installation:
Replace sealing ring.

Unlock quick-release coupling on coolant hose (5).

Detach coolant hose (5) and lay to one side.

Unfasten screws (2).

Tightening torque 11 51 1AZ.

Remove coolant pump (1) in upward direction with a tilting motion.

Installation:
Replace seal.

If reusing the coolant pump:
If a coolant pump is reused, it must be mechanically rotated once (breakaway torque at pump gears).

One coolant pump rotation will be sufficient.

If replacing the coolant pump:
Release screws on coolant thermostat.

Tightening torque 11 53 1AZ.





Remove coolant thermostat.

Installation:
Replace sealing ring.





Assemble engine.

Top up coolant.

Venting instructions must be observed without fail.