Air Cleaner Housing: Service and Repair

Special Tools, Testers And Auxiliary Items
- Hand Vacuum Pump VAG 1390

Test Conditions
- Temperature regulating flap vacuum unit not leaking.

Checking Regulating Flap
- Remove air cleaner upper section and take out air filter element.




- Place air cleaner upper section so that the regulating flap in the air cleaner lower section can be seen.
- Disconnect vacuum hose from the temperature regulator vacuum unit.
- Connect vacuum hose -3- to hand vacuum pump VAG 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 hose -3- to temperature regulator (brass connecting hose or with notch).
- Start engine and run at idle speed.




- Check position of regulating flap after maximum 20 seconds.




Temperature Regulator Comparison Chart