Radiator Cap: Testing and Inspection
Radiator cap valve1. Remove foreign material from radiator cap valve and the valve seat.
2. Attach radiator cap to a radiator cap tester. Apply pressure gradually to 15 psi (103 kPa).
3. Wait about 10 seconds. Verify that pressure has not decreased.
4. Replace radiator cap as necessary.
Negative pressure valve
1. Pull negative pressure valve to open it. Verify that it closes completely when released.
2. Check for damage on contact surfaces, and for a cracked or deformed seal.
3. Replace radiator cap as necessary.