Heating Air Conditioning: Removal & Installation Audi A8 D3 facelift 2

Preparation for heater core removal

1. Switch off ignition.
2. Dissipate pressure in coolant circuit by opening cap at coolant expansion tank. --> «19 - ENGINE - COOLING SYSTEM»(ref-289203-S15357943982008062700000) for 4.2 LITER V8 4V ENGINE MECHANICAL, ENGINE CODE(S): BVJ 19 - ENGINE - COOLING SYSTEM for 4.2 LITER V8 5V ENGINE MECHANICAL, ENGINE CODE(S): BFM «19 - ENGINE - COOLING SYSTEM»(ref-289204-S03664241582008062700000) for 5.2 LITER 10-CYL. 4V ENGINE MECHANICAL, ENGINE CODE(S): BSM «19 - COOLING SYSTEM»(ref-289206-S27114819052008062700000) for 6.0 LITER 12-CYL. 4V ENGINE MECHANICAL, ENGINE CODE(S): BSB
3. Remove left and right plenum chamber covers.
4. Remove engine control module and E-box cover. --> «97 - WIRING»(ref-289227-S18739568652008062700000)

1. Disconnect 2-pin connector from Coolant Pump V50 of pump valve unit --> «Pump/valve unit, removing and installing»(ref-289225-S19938788502008062700000) .

1. Mark the arrangement of coolant hoses - A - (supply to pump valve unit) and - B - (return to engine).
2. Clamp off two coolant hoses from engine to pump valve unit (e.g. using hose clamps V.A.G 3094).
3. Remove coolant hoses - A - and - B - from connections.

1. Connect one hose piece - A - and - B - to each of two connections.
2. Place container - C - beneath hose - B -.

1. Clamp off return from passengers side heater core - D - , e.g. using a hose clamp.
2. Using compressed-air gun, carefully blow coolant out of drivers side heater core and pump valve unit (into container).
3. Remove hose clamp from hose - D -.
4. Clamp off return from drivers side heater core - B - , e.g. using a hose clamp.

1. Using compressed-air gun, carefully blow coolant out of passengers side heater core and pump valve unit (into container).
2. Remove hose clamp from hose - B -.

Scheme 10

1. Loosen bolt - A - for coolant pipe holder (in plenum chamber) approx. 2 turns.
2. Remove coolant line bracket - B -.
3. Lightly coat contact surface of both coolant lines - D - and - E - at boot - C - with silicone lubricant (so that lines can be moved without changing position of boot).