[Healeys] BN2 Brake Problem

[Bob Spidell]

Listers,

I have a problem with my BN2's brakes that is driving (heh) me up the 
wall. Here's what I've done:

- new shoes and cylinders in both rear wheels
- one new cylinder in one front wheel (there's a total of 4 in the 2 
front wheels)
- new master cylinder

I hadn't touched the M/C, so after all the installs I just pressure bled 
as I usually do (this has worked well on my BJ8 for decades and a couple 
times for the BN2). At first, I got decent pedal then, after a period of 
time I lost it; the pedal would go to the floor with only slight 
pressure (probably from the return springs). Thinking it could only be 
the M/C, I sprung for a new TRW brand M/C but after installing it and 
bleeding I got the same results. I've put 2 full quarts of Castrol's 
finest 'synthetic' DoT4 through the system and tried vacuum bleeding and 
old-fashioned 'pump and hold' method; same result for all methods. I'm 
not losing fluid as far as I can tell, and the pedal will pump up a bit 
with a half-dozen or so strokes, but will go back to the floor after 
some time.

Any and all ideas and suggestions accepted and welcomed.

TIA,
Bob