F 150 4WD Pickup V8-302 5.0L (1986)
Air Injection Check Valve: Description and Operation
Air Check Valve/Pulse Air Valve
The Air Check Valve (Fig. 1) is a one-way valve that allows thermactor air to pass into the exhaust system while preventing exhaust gases from passing
in the opposite direction.
The Pulse Air Valve (Fig. 2) replaces the air pump application in some thermactor Systems. It permits air to be drawn into the exhaust system on vacuum
exhaust pulses and blocks the backflow of high pressure exhaust pulses. The fresh air completes the oxidation of exhaust gas components.
NOTE: Although the two valves share the same basic part number and have the same appearance, they are NOT INTERCHANGEABLE.
