Cap, Radiator: Inspection
| 1 - VENT VALVE |
| 2 - O-RING SEAL |
The vent valve (1) at the bottom of cap should be closed. A slight downward pull on the vent valve should open it. If the rubber gasket (2) is swollen and prevents the vent valve from opening, replace cap.
Hold cap at eye level, upside down. If any light can be seen between vent valve and rubber gasket, replace cap. A replacement cap must be the type designed for a coolant reserve/overflow system with a completely sealed diaphragm spring and a rubber gasket.