A buddy of mine called me tonight with a problem. He has an old chevy truck that he installed a power brake conversion kit on. He noticed a leak.

I went over and saw that it is leaking out the fitting in the prop valve. There is a big brass fitting that screws in the rear brake outlet port on the prop valve. It has a little rubber piece stuck down in the side of the fitting and a star spring retainer that holds that rubber piece in. That it where fluid is squirting from.

What is the purpose of this port? We removed the clip and rubber piece and there is a small port there