W150 1/2 Ton Pickup 4WD L6-225 3.7L VIN E 1-bbl (1982)
Thermal Vacuum Valve: Description and Operation
Coolant Control Exhaust Gas Recirculation (CCEGR)
1974-82 engines using EGR are equipped with a CCEGR valve mounted in the radiator top tank. When coolant temperature in the top tank reaches
65° F., the valve opens so that vacuum is applied to open the EGR valve. On some 1974-82 engines, a similar CCEGR valve set for 90° F. is
mounted in the thermostat housing.
