Thermal Vacuum Valve: Testing and Inspection

Place thermal vacuum valve in water heated to 115-129°F for 1985 I-Mark, 1985 Pickup and Trooper II with manual transmission and 1986-88 models or 113-131°F for 1985 Pickup and Trooper II with automatic transmission. Check to ensure valve is opened by applying air pressure. If valve is not opened, replace valve.Back Pressure Transducer
Apply approximately 2 psi of air pressure to port connected to back pressure transducer signal pipe and check for leakage. If leakage is noted, replace back pressure transducer assembly.