Cooling System - Coolant Leak From Coolant Flange
19 Coolant leak from coolant flange19 10 09
2018769/2
August 2, 2010
Supersedes Technical Service Bulletin Group 19 number 08-07 dated October 27, 2008 for reasons listed below.
Affected Vehicles
Condition
Coolant leak under hood from engine coolant flange.
Technical Background
The coolant leak is caused by the sealing O-ring for the coolant flange.
Production Solution
Improvement in the material of the sealing O-ring for the coolant flange.
Service
For A3 models:
In the procedure below, you will replace the sealing O-ring for the coolant flange.
1. Remove the engine cover and front sound insulation under the engine.
2. Drain coolant.
3. Disconnect the vacuum lines from brake booster and loosen wiring harness in the area of the flange.
4. Remove coolant flange from cylinder head (3 bolts).
5. Replace the O-ring and lubricate with coolant.
6. Reinstall the coolant flange. (Torque bolts to 10 Nm.)
7. Secure the wiring harness. Reinstall all the wraps and clips.
8. Reconnect the vacuum line.
9. Refill coolant and check cooling system for proper operation.
10. Reinstall the engine cover and sound insulation.
For A4 models:
In the procedure below, you will replace the sealing O-ring for the coolant flange.
1. Remove the engine cover and front sound insulation under the engine.
2. Drain coolant.
3. Loosen the wiring harness at rear of engine and remove harness brackets.
4. Remove the U-shaped crankcase breather tube.
5. Remove the upper coolant metal pipe attachment screws.
6. Remove the hose clamp and free rear coolant hose to coolant flange from metal pipe.
7. Move the coolant metal pipe as far as possible to driver's side.
8. Unplug the coolant temperature sensor electrical connector.
9. Remove the heater core hose from the coolant flange.
10. Remove coolant flange from cylinder head (2 bolts).
11. Replace the O-ring and lubricate with coolant.
12. Reinstall the coolant flange. (Torque bolts to 10 Nm.)
13. Reinstall hoses, pipes and tubes.
14. Reinstall harness brackets, secure the wiring harness. Reinstall all the wraps and clips.
15. Refill coolant and check cooling system for proper operation.
16. Reinstall the engine cover and sound insulation.
Warranty
Required Parts and Tools
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.