[T2] Disc brakes dragging

[Chris Dreike]

Hi Guys,
I put this up once before but I still have a problem. This is on my 71 Bay
with power disc brakes. The booster, master cylinder, brake hoses, brake
cylinders, calipers are all new. I installed empi drop spindles a couple
months ago. Ever since the disc brakes are slowly closing up and dragging.
Before I start the engine, with the parking brake off, I pump the brakes 10
times. By the 10th pump the the pedal goes down about 1/3-1/2 way and feels
good. It goes down smoothly. The bus will roll forward or back on the
slightest slope, so the brakes are free.

 I start the engine and drive off. After a bit of driving and using the
brakes, the pedal goes hard very near the top of stroke and the discs are
dragging slightly. I can stop, shut off the engine and pump 10 times and
the brakes free up once again.

I bled the brakes myself when I installed everything and today I took it to
my trusted mechanic who also bled the brakes and made sure the rear brakes
are properly adjusted. I still have the same problem.

Any ideas on what may be going on? I have the original proportion valve
installed. What is the deal with a valve in the master cylinder? Is there
one in the 71? Should I remove it? Could the booster have a leak? I
adjusted the pedal to booster rod so there is a small gap between it and
the booster.

Thanks,
Chris
64 DD Kamper Kit
71 sunroof