does anyone know if the OEM master cylinder contains an intergal residual pressure valve?

http://www.oreillyauto.com/site/c/detail/A1C0/1040000/01292.oap?year=1966&make=Chevrolet&model=C30%2BPickup%2BRWD&vi=1321951&ck=Search_01292_1321951_-1&pt=01292&ppt=C0066

apparently, the drums have been turned so many times now that normal shoes cannot reach the drum in one pump of the pedal.
one pump = very little brakes
second pump = locked wheels




o

Last edited by john_brunson; 10/11/2012 10:23 AM.