Rubber Valve

Fig 1: Identifying Rubber Valve Stem Components

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

1. Valve body
2. Valve core
3. Valve cap

1. Valve Body

The rubber valve for tubeless tires is designed to seal air-tight in the hole in the rim. The elastic material of the rubber body presses itself tightly into the hole in the rim.

When valves with threaded metal feet are used, a rubber seal is used to seal the rim. The area around the edge of the valve hole is a sealing area. Therefore, they must be free of rust, dirt and damage.

2. Valve Core

The valve core has the most important job in the valve. It creates a seal and enables the regulation of the air pressure. The small plate seal on the valve core can only do its job when it is free of impurities, dirt and moisture. The compressed air system must be free of water and oil!

3. Valve Cap

A valve cap must always be screwed onto the valves. It prevents dirt from getting into the valve. Dirt which may be in the valve would reach the seal of the valve plate when the tire is inflated and cause a leak.

The valve must be replaced every time a new tire is fitted.

If the vehicle is driven without caps on the valves, there is the danger that dirt may get into the valve. This leads to gradual loss of air and therefore lead to the destruction of the tire:

• Separation of carcass and rubber, refer to Figure.
• Wide circumferential furrows in the area of the bead, refer to Figure.
• disintegrated tread or torn-out tread, refer to Figure.