Yes it has residual valves off the master, M.C. and booster mounted on frame. Stainless brake lines in front. Small cam. I've had the car a couple years and the pedal has never been great but the brakes always worked okay. Thanks everyone for sticking with me on this.
When the engine dies you should have one or two power assisted stops before all the vacuum is gone from the reservoir.
More often than not I see builds done where guys have cabin fitting issues so they unknowingly modify the brake system so it fits better but compromised the way it’s supposed to work. I’ve seen jacked up pedal ratios, short strokes, jack shaft style pedals, wrong bore ratio math, and general nincompoopery. Funny thing I’ve been able to fix every one so far. Sometimes it involves cutting the car and fabricating the stuff right. Sometimes just swapping the right combo of parts. Maybe that’s your problem here with a “never been great” pedal. What’s that mean exactly. Try a bleed with an experienced helper. when the bleeder opens the pedal has a “feel” to the drop.
Provided that “all of the everything else” stuff is there and working as it is designed and the booster is the proper size to begin with emulating a OEM set up. All of that is seldom found in a hot rod. I always overbuild seat mounts and sometimes people ask why. My answer is I can’t tell how hard the driver will need to be standing on the brakes.
Not stops, pumps on the pedal. Assuming you weren't on the brakes already. My guess is everyone has had to do a non-assisted stop at one time or another.
Aha... may be more here than just the master cylinder. It might still need to be fixed or replaced. Then some further investigation. Readjusting the rod. Look at the threads on the rod. You may be able to see where it was adjusted to. Maybe not. But you should have a little bit... as much as 1 inch of free play at the top of the pedal before you feel any added resistance. Sent from my VS835 using The H.A.M.B. mobile app
If the pedal pumps up and drops, the master is bypassing internally. Some are elusive to diagnose, others like yours are obvious.
SUCCESS, I tried again today and checked rear drums for adjustment. I did the right side first no problem, then switched to the left and as I was taking the plug out I noticed a very small amount of fluid on the drum by the bleeder, I called my wife and she stepped on the pedal , as I watched the bleeder sure enough a drop maybe two leaked out . After that we bled the brakes and all seems good . I took it for a drive no problems. I really feel stupid not catching this sooner. If all of you hadn't suggested I check the rears I'd still be chasing shadows.