Campaign - Water Pump Leak

Service Measure

Engine

M11 200 03

2/11/2003

Subject
Coolant leak from water pump mounting flange

Complaint
Coolant leak from water pump mounting flange
Vehicles concerned: R53 with W11
Production period: Series launch up to 11/02

Cause
The connection between the water pump housing and the mounting flange on the crankcase is leaking.
The rubber O-ring has been crushed on one side by incorrect centering of water pump to mounting flange.

Measure
1. In case of customer complaint replace the two O-rings, part number 11 51 7 509 186.

2. Apply "Syntheso Glep 1" to the O rings, part number 83 23 9 407 778.

3. Refer to repair manual group 11 section 11 51 00 for proper water pump O ring replacement.

4. The following alignment procedure should be done in sequence:

a. align water pump to supercharger and tighten. refer to tech data for torque specifications.

b. align water pump to mounting flange and tighten flange. refer to tech data for torque specifications.

c. align supercharger to mounts and tighten. refer to tech data for torque specifications.

5. In case of coolant leak caused by water pump/flange misalignment, it is not necessary to replace water pump.