Cooling System Bleeding Audi A6 C5

Scheme 3

1. Expose vent hole on heater pipe, at firewall connection, by pulling back heater hose. (Scheme 3) Fill cooling system through expansion tank until coolant comes out of vent hole. Tighten heater hose.
2. Fill expansion tank to proper level. Loosen bleeder screw on lower coolant hose, located under expansion tank. Unbolt expansion tank if necessary. Top off coolant until it flows from bleed screw. Close bleed screw.
3. Fill expansion tank to proper level. Loosen bleed screw on front coolant line between power steering pump and left of cylinder head. Top off coolant until it flows from bleed screw. Close bleed screw.
4. Fill expansion tank to proper level. Install expansion tank cap. Start engine and raise engine speed to 2000 RPM for about 5 minutes. Return engine to idle. Check coolant level in expansion tank. Fill as necessary.

A6

1. Inspect coolant lines for bleed screws. One is located at front of engine near the upper hose connection. Loosen bleed screws front and on rear coolant pipe.
2. Expose vent hole on heater pipe at firewall connection by pulling back heater hose. (Scheme 3) Fill cooling system through expansion tank until coolant comes out of vent hole and bleed screws. Tighten heater hose and bleed screws.
3. Fill expansion tank to proper level. Install expansion tank cap. Adjust heater controls to maximum heat position. Start engine and raise engine speed to 2000 RPM for about 3 minutes. Ensure cooling fan operates. Return engine to idle. Check coolant level in expansion tank. Fill as necessary. Repeat and recheck.