No promises, but this sounds reasonably accurate... and I took it right off Amazon.com for the Stant 10331 Lev-R-Vent Radiator Cap - 16 PSI
Vented 
http://www.amazon.com/Stant-10331-Le.../dp/B000B8LKZ0
Quote:
|
Stant LEV-R-VENT radiator caps fit in the smaller spaces of today's engines, while providing a pressure release lever and may fit on applications where older, larger-shell caps may not. A tab on the bottom of the lever interlocks with the filler neck to prevent removal of the cap until the lever is lifted. When the lever is lifted, the entire pressure valve is lifted off the lower sealing seat in the filler neck, harmlessly venting pressure through the overflow tube.
|