Tyre Valve

Rubber snap-in valves are common; metal valves are used with TPMS. A valve core inside seals the air. Caps keep dirt out. A slow leak at the valve can be found by spraying soapy water on it. Valve cores can be tightened or replaced with a small tool. Metal TPMS valves need the correct torque on the nut and new seals when tyres are changed. Missing valve caps let dirt in and can cause leaks.

The spring-loaded core opens when pressed by the air line.

Old rubber valves crack and leak. Replace valves when fitting new tyres.