Exhaust Emissions System - Thermostatic Air Cleaners: Testing
Remove the air filter housing and filter element. Dip the filter housing into cold water as deep as the thermostatic element. After being immersed for 5 minutes in water below 66°F (19°C), the air flap should have closed off the cold air passage. Heat water to above 95°F (35°C). After a short time, the thermostatic element should expand and the flap should close off the hot air intake passage.