Auxiliary Water Pump: Service and Repair

Water pump engine coolant heater, replacing

Special tools:
951 2649 Crimping tool 951 2649 Crimping Tool
951 2620 Stripping tool 951 2620 Stripping Tool

Note! The illustrations in this service information are used for different model years and/or models. Some variation may occur. However, the essential information in the illustrations is always correct.

Preparatory work

Important information
When replacing with a new water pump, the water pump wiring must be extended and a rubber cap placed on the new water pump. The rubber cap is included in service kit P/N 373 0575.
If the car already has the new type of water pump, the above adjustment is not required.

Removal

Removing the bumper cover, air baffles and combustion preheater module (CPM)
Remove the bumper cover. See: Casing, bumper front, replacing Service and Repair.





Remove:
- the air baffles on the left-hand side and on certain versions also on the right-hand side
- the air baffle in the center.




- the combustion preheater module (CPM) from the mounting by slackening off the screws
- the connector from the control module.

Removing the water pump




Install hose clamps on the hoses connected to the water pump.
Position a container under the water pump to collect the coolant.
Disconnect the hoses.
Remove the connector.




Remove the 2 nuts retaining the pump holder.

Note! Note the position of the water pump on the holder.

Hold the damper. Pull the water pump off.

Adjustment

Extending the wiring for the water pump




Cut off the cable harness for the water pump as close to the connector as possible.
Cut off part of the protective tube so that the 2 cables are exposed.
Strip the ends of the cables enough for the bonded shrink-fit terminals from the kit.




Modify the length of the protective tube so that the stripped cable ends are only just protruding.
Thread the thin protective tube onto the cable harness extension.
Use the bonded shrink-fit terminals from the kit. Splice the cable harness extension to the stripped cables.

Note! The cable colors must match at each join.

Reinforce the exposed areas. Use insulation tape.




Thread the thicker protective tube from the kit over the join.
Adjust the length so that it overlaps the thinner protective tubes by approximately 10 mm on each side.
Wind insulation tape around the join.

Installation

Installing the water pump and rubber cap




Thread the new water pump into the existing rubber mounting using the marking made earlier.
Wind foam tape from the kit around the section of the water pump protruding from the rubber mounting.




Install the water pump and rubber mounting on the screws for the engine block heater.
Route the water pump wiring as illustrated.
Connect the connector to the top of the water pump.
Thread the rubber cap from the kit over the cable harness and the upper section of the water pump.
Secure the rubber cap. Use the tie strap from the kit.

Installing components

Install:
- the hoses on the pipe couplings for the water pump. Tighten the hose clamps
- the bracket for the control module. Tighten
- the control module.
Remove the hose clips from the hoses. Check that there is no leakage.

Install:
- the air baffles on the left-hand and, if applicable on the right-hand side
- the air baffle in the center
- the bumper cover. See: Casing, bumper front, replacing Service and Repair.

Finishing

Testing the engine coolant heater
Test run the engine coolant heater. See: Engine coolant heater, test running Engine Coolant Heater, Test Running.

Note! The water pump may beep for a short while due to air in the system. Check the coolant level in the expansion tank. Top up if necessary.