Audi Workshop Service and Repair Manuals

Checking combination valves for secondary air system for correct operation and leakage Special tools and workshop equipment required

t  Hand-operated vacuum pump with accessories -V.A.G 1390-

Procedure –  Unfasten screw connections -arrows- and detach engine cover panels -A ... C-.

–  Unscrew hose connections and bolt connections on the air duct at the points indicated by -arrows- and remove the air duct.

Combination valve for secondary air (left-side): –  Unbolt coolant expansion tank -2--arrows-. –  Unplug electrical wire for coolant shortage indicator switch -F66- at bottom of expansion tank and move expansion tank to one side with coolant hoses -1- and -3- attached.

Combination valve for secondary air (right-side): –  Remove cover -1- at right of engine compartment.   Note Disregard items marked -2- and -3-.

Continued for both combination valves for secondary air system: –  Detach air intake hose -3- and vacuum hose -2- from relevant combination valve for secondary air system.   Note Disregard -item 1-.

–  Connect suitable hose -arrow- to air intake hose connection on combination valve for secondary air.

–  Connect the hand-operated vacuum pump -V.A.G 1390- to vacuum connection of combination valve for secondary air. –  Blow gently into hose (do not use compressed air). l  The combination valve for secondary air system should be closed; it should not be possible to blow through the hose. –  Use hand-operated vacuum pump to generate vacuum. l  The combination valve for secondary air system should open; it should now be possible to blow through the hose. If combination valve for secondary air system does not react as described: –  Renew combination valve for secondary air system: on left-side → Chapter, on right-side → Chapter. Installation is carried out in the reverse order; note the following:   Note Secure all hose connections with the correct type of hose clips (same as original equipment) → Parts catalogue. Tightening torque

Component	Nm
Air duct to intake manifold	10