Heater Core: Service and Repair

Heater Core

Special tools, testers and auxiliary items required

• Drip Tray For Workshop Hoist (VAS 6208)

• Hose Clamps Up To 25 mm Diameter (3094)

• Engine Bung Set (VAS 6122)






• Compressed air gun, commercially available

Removal

- Turn off all electric consumers.

- Switch off the ignition.

- Remove the key.

Follow all Safety Precautions when working on airbag units, seat belt tensioners and battery cut-out units (pyrotechnical components).

- Remove the instrument panel.

- Remove the vehicle electrical system control module.

- Completely detach the module carrier..

- Remove the driver footwell vent. Refer to => [ Footwell Vent, Driver Side ] Footwell Vent, Driver Side.

- Pull the module carrier forward off the studs.

- Cover the studs on the right side with a cloth or the like.

- Press the module carrier up on the right side and place it on the studs.

• Bleed the coolant circuit after it has been opened.

• The coolant system is under pressure when the engine is warm. If necessary, release system pressure prior to repair work.

- Place (VAS 6208) under the engine.

- Discharge the coolant circuit.

- Label the coolant hoses to the heating and A/C unit.

- Disconnect the coolant hoses to the heater core of the heating and A/C unit (for example, with the (3094) ) and remove.

- Insert one section of hose - A - and of - B - on to both connections to the heater core.






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

- Using a compressed air gun - D -, carefully blow coolant out of the heater core (into container - C -) via hose - A -.

- Pull the interior carpet on the left away from the center tunnel.

- Remove the heater core cover - 1 -.

- Remove the bolts - 2 - and loosen the tabs - arrow -.






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

The coolant system is under pressure when the engine is warm!

There is a risk of scalding from hot steam and coolant.

To reduce the pressure, cover the coolant reservoir cap with several cloths and then open it carefully.

- Pry retaining clips - 1 - off the coolant lines.






- Slowly remove the coolant lines from heater core and allow escaping coolant to run into an accumulator reservoir.

• There is a fastening pin on the left side below the heater core. This connects the lower heater core with the heating and A/C unit.

- Pull fastening pin - 1 - out of the locking mechanism - arrow A - and then pull out the fastening pin in the direction of - arrow B -.






- Fold the cover down and remove the heater core to the left.

Installation

- Install the heater core in the reverse order.

• Always replace the O-rings.

- Secure all connections with the same type of clips used in series production. Refer to Electronic Parts Catalog (ETKA).

- After installing the retaining clips, make sure they are securely seated - arrows - on the heater core.