Heater Core: Service and Repair

Heater Core

Special tools, testers and auxiliary items required

• Drip Tray For Shop Crane (VAS 6208)

• Hose Clamps Up To Diameter 40 mm (VAS 3093)

• Compressed Air Gun, Commercially Available

Removal

- Remove the bulkhead in the plenum chamber.

- Place (VAS 6208) under the engine.







Contact with hot engine coolant can cause severe scalding.

Coolant temperature can be above 100 °C with a warm engine. The cooling system is under pressure.

If necessary, reduce pressure and temperature before repairs.

- Clamp the coolant hoses - 1 - using the (VAS 3093) and remove the coolant hoses from the heater core.






- Connect a section of hose - A - to the upper connection on the heater core.

- Hold a container - B - under the lower connection - C -.

- Using a compressed air gun, carefully clear out any coolant still inside the heater core into the container - B -.






- Loosen the bolt - 1 - (do not remove it completely) from the connection flange between the heater core connections.

• This allows the coolant pipes to move for removing the heater core.

- Remove the footwell trim on the driver side.

- Remove the left footwell vent. Refer to => [ Left Footwell Vent ] Left Footwell Vent.






- Remove the bolts - 1 - and remove the heater core trim.

- Cover the carpet the in area under heater core with waterproof foil and water absorbing paper.






- Open the clamps - A - and disconnect the coolant pipes.

- Remove the heater core from the heater housing.

Installation

Installation is carried out in the reverse order while noting the following:






- Check the seals - A - and - B - on the heater core for damage.

• An incorrectly glued seal can roll up into heater housing when sliding in the heater core.

• Cold air may flow past heater core if seal is damaged or not properly fitted.

- Check the heater housing (while the heater core is removed) through the heater core opening - A -, for dirt.






- Remove any dirt or coolant which has leaked out of the heater (for example, after removing a leaking heater core).

- Install the heater core into the heater housing.

- Coat sealing rings - 1 - with coolant before installing.






- Install the seals - 1 - into the coolant pipe connections.

• If hose clamps are deformed, replace them.

- Connect the coolant pipes.

- Hose clamps - A - must be able to be twisted slightly when installing onto the coolant pipes.






- Tighten hose clamps - A - to 2.0 Nm.

- Check seating of both clamps - A - after tightening bolts, clamps must enclose the flange on coolant pipe completely and must not touch other components.






- Tighten the connection flange bolt - 1 - between the heater core connections to 2 Nm.

- Make sure the grommet - C - fits correctly inside the plenum chamber bulkhead.






- Seal flange for coolant pipes to heater core - A - and for expansion valve (to evaporator, only in vehicles with A/C system) - B - at pass-through of grommet - C - with silicon adhesive sealant if necessary (to prevent water from penetrating).

• Replace the seals.

• If hose clamps are deformed, replace them.

• Replace all the coolant after replacing the heater core.

• Check coolant circuit for leaks, pay particular attention to the connection between coolant hoses and heater core.