Thermostat: Service and Repair

Thermostat, replacing

Special tools:
951 2957 Coolant Reservoir 951 2957 Coolant Reservoir
951 2953 Cover 951 2953 Cover

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.

Note! Raise the vehicle as described in Jacking points, body Service and Repair.

Removal

Preparatory work
Remove the expansion tank cap.
Raise the vehicle as described in Jacking points, body Service and Repair.

Removing protective plate





Note! There is a guide sleeve on the upper mounting for the plate. This must be lifted slightly so that the panel can be slid forward.

Remove the 6 screws.
Lift and slide the protective plate forward.
Remove the protective plate.

Draining coolant
Open the cock on the lower left edge of the radiator.
Drain the coolant into a clean receptacle.
Close the cock.

Installing the protective plate





Install:
- the protective plate
- the 6 screws; tighten.

Removing the lower engine cover





Remove:
- the 6 screws
- the lower engine cover.

Removing the thermostat





Note! Some coolant will escape from under the thermostat housing when the screws are loosened; wipe it up with paper or the like.

Remove:
- 2 screws from the thermostat housing cover. Bend aside the radiator hose.

Hint: The upper screw can be loosened more easily from above.

- the thermostat.

Installation

Note! For tightening torques, see: Tightening torque, B8444S Tightening Torque.

Installing the thermostat

Install:
- a new thermostat with a new gasket
- the cover with radiator hose. Tighten the 2 screws.

Installing the lower engine cover





Install:
- the lower engine cover
- the 6 screws; tighten.
Lower the vehicle.

Check

Caution! Make sure the outlet hose of filling equipment is not blocked as this could damage the cooling system.

Fill with coolant using filling equipment 951 2957 Coolant Reservoir 951 2957 Coolant Reservoir and cover 951 2953 Cover 951 2953 Cover.
Start the engine and allow it to warm to normal operating temperature. Check for leaks and proper function. Fill up fluid as necessary.