Removing and installing heat exchanger with air conditioning unit (rear) installed — AUDI

🧭 Before you start

Fits: Audi Q7 (4L, 2005–2015)

Don't miss

• Mark the two coolant hoses (A) and (B) to the rear heat exchanger (C) (danger of interchange).
• Check the foam seals at the heat exchanger (A) (must be bonded on tightly and not damaged).
• Correctly connect up the coolant hoses: Coolant hose (B), supply from engine (via pipe assembly beneath left wing) and coolant hose (A), return to engine (via pipe assembly beneath left wing)
• Fill the coolant expansion tank with coolant as far as the upper mark Engine, mechanics19.

📋 Procedure

1. Switch off ignition.
2. Release pressure in coolant circuit by opening cap on coolant expansion tank Engine, mechanics19.
3. Move air conditioning unit (rear) to service position .
4. Remove the rear left air quantity flap control motor V239.
5. Remove the rear right air quantity flap control motor V240.

6. Remove the bolts (A) and detach the upper cover (B).
7. Mark the two coolant hoses (A) and (B) to the rear heat exchanger (C) (danger of interchange).
8. Pinch off the two coolant hoses (A) and (B) to the rear heat exchanger (C) (e.g. using hose clamps up to dia. 25 mm3094).
9. Unfasten the heat exchanger (C) from the air conditioning unit.
10. Use absorbent paper to cover the area beneath the air conditioning unit into which escaping coolant could ingress (to stop any coolant escaping running onto and into the air conditioning unit or onto the floor covering).
11. Place a vessel beneath the two connections to the heat exchanger (C) and detach both coolant hoses.
12. Clean the rear air conditioning unit (e.g. to remove residual coolant).
13. Check the foam seals at the heat exchanger (A) (must be bonded on tightly and not damaged).
14. Insert the heat exchanger (C) in the air conditioning unit.
15. Attach the coolant hose (B) to the coolant pipe to the heat exchanger (C) (coolant hose (A) is not connected yet). [Note: Correctly connect up the coolant hoses: Coolant hose (B), supply from engine (via pipe assembly beneath left wing) and coolant hose (A), return to engine (via pipe assembly beneath left wing)]
16. Fill the coolant expansion tank with coolant as far as the upper mark Engine, mechanics19.
17. Use absorbent paper to cover the area beneath the air conditioning unit into which escaping coolant could ingress (to stop any coolant running onto and into the air conditioning unit or onto the floor covering).
18. Place a vessel beneath the connection (A) to the heat exchanger (C).
19. Slacken off the hose clamps up to dia. 25 mm3094 at the coolant hose (B) to enable the coolant to flow slowly into the heat exchanger (to pre-bleed the heat exchanger). [Note: If the coolant does not flow automatically into the heat exchanger, build up pressure in the coolant expansion tank using the hand pump of the cooling system testerV.A.G 1274 for example to accelerate the flow process.Pre-bleeding of the coolant circuit considerably simplifies the bleeding of the cooling system on initial commissioning following installation .]
20. Wait until coolant emerges from the connection for the coolant hose (A) at the coolant pipe to the heat exchanger.
21. Attach the coolant hose (A) to the coolant pipe to the heat exchanger.
22. Re-install components in reverse order of removal.
23. Bleed coolant circuit and Engine, mechanics19

Other AUDI procedures

• Removing and installing toothed belt – Audi · 56 torque figures
• Removing engine – Audi A8 D3 · 41 torque figures
• Removing camshaft timing chain from camshafts – Audi A6/A7 C7 · 38 torque figures
• Installing engine – Audi A8 D4 · 36 torque figures
• Removing and installing camshaft timing chain · 29 torque figures
• Checking steering system for leaks – Audi A2
• 5-speed manual gearbox 01A, four-wheel drive — Removing and installing rear final drive
• Removing and installing combination valve for secondary air system (left-side)
• Removing and installing combination valve for secondary air system (right-side)
• Removing and installing coolant distributor housing with thermostat, engine code BVY, BVZ · 1 torque figures