Description

Coolant Expansion Tank Cap – pressure cap for the cooling system expansion tank, rated at 15 psi.

The cap seals the expansion tank and regulates system pressure: it holds the circuit at its working pressure to raise the coolant boiling point, venting through an integral relief valve once 15 psi is exceeded. As the engine cools, the vacuum valve allows coolant to be drawn back into the circuit, maintaining the correct system level.