Another "brake help" thread...

Crossed lines into the Combination valve?
OR
the front brakes just not working.

>You must have a high, hard pedal, on the first pump. That proves the system is free of air.
>with the car stopped, IF it takes multiple pumps to achieve a hard pedal;
1) the rear shoes are out of adjustment and/or
2) the front pistons have retracted too far.
>The Compensating port must be open with the pedal parked.
The REAR-most chamber drives the FRONT brakes thru the TOP of the C-valve, which is just a Splitter section.
>At the Caliper brackets, the calipers must be free to slide back and forth on their "ways". and the Pads must be semi-floating the brackets. and, the two pads must sit flat on the rotors.
> the caliper-pistons and pads, have to be parallel to the faces of the rotors. If they have to be twisted by the force of the brake fluid, that takes pedal-travel to accomplish.
>Finally, the rotors better have the right bearings in them, and them adjusted correctly, to keep them concentric to the not-bent spindles. This is actually where it starts, cuz if your pistons are getting knocked-back into the calipers, by rotating parts, that's gonna take more than one pump, just to advance them, and if the car is moving, every time you go for anther pump, the pistons retreat, ot get knocked back
>Multiple pumping of the brake pedal, speaks to excessive pad/shoe travel; usually in the rear system, but in your case, I'm betting on it being in the fronts.
>Brakes sticking on, points to the fluid NOT returning to the M/C.
My usual guess would be a residual valve still in the M/C, or in your case, more likely is that the PowerPiston inside the M/C is not returning far enough towards the firewall, most likely because of a misadjusted and too long pushrod , or could be a pedal not parking high enough, or a faulty C-Port. At rest, the Compensating Port HAS To be open.
>intermittent sticking-on, can also be a kinked front flex hoses, while turning.
>At the back, noise indicates something is wrong there, figure it out.
Btw modern w/c's do not actually need the hold-off/residual valve in the M/C, altho, leaving it there hurts nothing, so long as it is assembled correctly.
As for Oval drums; I doubt that is your problem.

This list may not be complete, just all I can think of just now.
My best guesses are in bold

Happy HotRodding