Volkswagen Workshop Service and Repair Manuals

Checking regulating flap

• ● Regulating flap vacuum unit not leaking

• ‒ Loosen air cleaner upper part and remove filter element.
• ‒ → Check position of regulating flap.
       Regulating flap must close-off the warm air intake -2-
• ‒ Pull vacuum pipe from vacuum unit -4- off temperature regulator -3- (in air intake elbow).
• ‒ Connect vacuum pipe to hand vacuum pump V.A.G 1390.
• ‒ Operate pump and check ease of movement of the regulating flap and function of the vacuum unit.
       Regulating flap must close off the cold air
       intake -1-

Checking temperature regulator

• ‒ Connect vacuum pipe to temperature regulator.
• ‒ Start engine and run at idling speed.

• ‒ → Check position of regulating flap after max. 20 seconds.