Thermostatic Air Cleaner: Testing and Inspection

Control flap, checking

Requirement
- no leaks in control flap vacuum unit

- loosen air filter housing upper section and remove air filter element







- position air filter housing upper section such that the control flap in the lower section housing can be seen
- disconnect vacuum unit hose from temperature controller on intake air boot
- connect vacuum unit hose to US 8026 hand vacuum pump

- operate vacuum pump to check control flap freedom of movement and vacuum unit function
- control flap must close OFF cold air pipe 1

Temperature regulator, checking

- connect vacuum unit hose to temperature controller connector nipple on intake air boot

- start engine and let idle
- position of control flap after 20 seconds (maximum), depending on temperature controller temperature:
- below approx. 20°C (68°F) cold air pipe 1 closed
- above 30°C (86°F) = warm air pipe 2 closed
- between 20°C and 30°C (68 to 86° F) = control flap between cold and warm air pipes (both pipes open)