Coolant Vacuum Switch
- Disconnect molded connector from valve and attach a 1/8" I.D. hose to bottom port of valve. With radiator top tank warm to touch (no warmer than 75°F), blow through hose. If air cannot be blown through valve, replace valve.
- Bring engine to normal operating temperature. Attach a vacuum pump and gauge to bottom port of valve. Apply 10 in. Hg of vacuum. If vacuum level drops more than one inch in 15 seconds, replace valve.