Hey all, sorry for another brake question but as I have been reading and searching through the threads, I haven't seen enough to confirm to myself that I am moving in the right direction here.

Truck is a 1968 C50. Brakes are of the standard issue variety with a single pot master under the hood. The master is bolted to the brake booster which is bolted to the firewall.

Last year I found the master cylinder to be failing (booster was half full of brake fluid) so I replaced it and could never get a pedal back. The truck sat over the winter and spring and I have picked back up on it this week. After days of frustration with literally no pedal, I spent about half a day with a vacuum pump bleeding the heck out of the brakes.

The good news: I have somewhat of a pedal and the truck WILL stop. This is a major advancement from earlier in the week when it was doing a whole bunch of nothing.

The bad news: The pedal is actuating the brakes really low to the floor and a couple seconds after the truck has stopped the pressure seems to bleed off and the truck will roll again if I do not put the parking brake on.

I had to throw in the towel for today but the fact that the brakes are doing something is a positive (at least in my book.

My questions:

I want to do another round of vaccuum bleeding. That's a good idea, right?

I am assuming that the shoes need adjusting to get the pedal to "pick up" earlier and get said shoes against the drums and working to slow me down. With limited time I was fishing around with a slightly wimpy slotted screw driver to try and move the adjusters but had no luck. I am hoping the right tool will do me better.

The pressure bleed freaks me out and I should note, when that happens, the pedal is on the floorboard. It isn't bleeding the pressure and causing the pedal to drop....it is all the way there already.

I have seen a couple guys that talked about installing a residual pressure valve. I am contemplating this fix if you all think that the valve in the rebuild Midland (PN 300358) master is not working.

Thanks everyone!

Brian