:: ENGINE PROBLEM ::

A cylinder head vacuum tester is used for two purposes. One to quickly check if valves have a satisfactory seal when examining the head for repairs. This test is carried out with the valve springs still fitted and only indicates the ability of the valve to seal compression. This test used in this manner does not check the concentricity of the valve and seat or its condition as the valve spring tension will overcome minor faults. This assembled test is simply a guide to the general condition of the valve and seat and to the condition of the port. In this test a pad seals against the port face and a vacuum pump creates a vacuum in the port to the valve seat. Holes in ports can be identified before work commences on the head. The second use is to check the concentricity and conformity of newly machined valves and seats. This test is carried out without the springs fitted with the machined valve simply resting on the seat. This ensures 100% seal and extended valve life.