Heating Air Conditioning: Removal & Installation Audi S8 D3 facelift

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 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 for 5.2 LITER 10-CYL. 4V ENGINE MECHANICAL, ENGINE CODE(S): BSM 19 - COOLING SYSTEM 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

1. Disconnect 2-pin connector from Coolant Pump V50 of pump valve unit --> Pump/valve unit, removing and installing .

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).