Heater Core: Service and Repair

Heater Core

Special tools, testers and auxiliary items required

• Drip Tray For VAS 6100 (VAS 6208)

• Hose Clamps Up To 40 mm (VAS 3093)

• Compressed air gun, commercially available

Removing

- Remove the bulkhead inside the plenum chamber.

- Place the (VAS 6208) under the engine.







Contact with hot engine coolant can cause severe scalding.

Coolant temperature can be above 100 °C (212 °F) with a warm engine. The cooling system is under pressure.

If necessary, reduce pressure and temperature before repairs.

- Clamp off 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 -.






- Remove the bolt (6 mm inner hex) - 1 - from the connection flange between the heater core connections.

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

- Remove driver side footwell trim, if equipped.

- 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.

- Remove the clamps - 2 - and then remove the coolant pipes - 1 - from the heater core.






- Remove the heater core from the heater.

Installing

Install in reverse order of removal. When doing this, note the following:






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

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

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

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

- Coat sealing rings - 2 - with coolant before installing.






- Install the seals - 2 - for the coolant pipe connections - 1 -.

- Attach the coolant pipes to the heater core.

- Install the clamps - 3 -.

- Thread the bolt - A - into the connection flange - B - and while doing this make sure bolt is actually threaded into the mounting point intended for it.






- Make sure the grommet - C - fits correctly inside the 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).

• Sealing rings must always be replaced.

• If hose clamps are deformed, replace them.

• After replacing the heater core, coolant must be replaced completely.

• Check the coolant circuit for leaks. Pay attention to the connection between the coolant pipes and the heater core.