Volkswagen Workshop Service and Repair Manuals

Special tools, testers and auxiliary items

• ◆ Hand vacuum pump V.A.G 1390

Checking regulating flap

Test conditions

• ● Regulating flap vacuum unit not leaking

• ‒ Remove air cleaner upper part and take out air filter element.

• ‒ → Place air cleaner upper part so that the regulating flap in the air cleaner lower part can be seen.
• ‒ Pull vacuum pipe off the temperature regulator vacuum unit.
• ‒ Connect vacuum pipe -3- to hand vacuum pump V.A.G 1390.
• ‒ Operate pump and check freedom of movement of regulating flap and function of vacuum unit.
       Regulating flap must close off cold air intake -1-.

Checking temperature regulator

• ‒ Connect vacuum pipe -3- to temperature regulator (brass connecting pipe or with notch).
• ‒ Start engine and run at idling speed.

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