Coolant Loss Past Pressure Cap Top Seal (on Filler Neck)

1. With normal gauge reading.
^ Pressure cap not installed tightly.
^ Pressure cap top seal leaks.
^ Pressure cap diaphragm bowed.
^ Damaged radiator filler neck.
^ Pressure cap top seal out of position.

2. With high or low gauge reading on new vehicle.
^ Kinked coolant reserve system hose.
^ Coolant reserve system tank plastic tube plugged.
^ Pressure cap seal out of position.