Power Brake Issues on an AD

[Hampshire]

About a year and a half ago we put this frame mounted booster/master kit in my 1949 AD for my disc/disc setup.

http://www.mpbrakes.com/1949-chevrol...1?filter_name=

MPB was helpful & we ended up we a great setup properly configured with a proportioning valve, etc. Ran it for a season (about 1200 miles) with no problems. The truck went into the shop for an engine swap & frame mods. We had to cut/replace rear brake line and relocate the vacuum to the of the new motor. (6/V8 swap).

Months later we finish up, bleed the system and no brakes when we fire it up. We check the vacuum and it's within spec at 19-20+. We call MPB and per their instructions we first check the integrity of the vacuum line while it's running (no collapses). Still per MPB, we bleed each caliper again and then every joint at the master, etc. Same story - we get some pedal but as soon as we start up the truck the pedal bottoms. Per their instructions, we even try it with two of the outlets at the master plugged - still no dice.

So, we end up paying almost full retail for a new booster (yes, it was over a year old and out of warranty) which I'm now waiting for....

My questions to the forum:

- Do you think it's a faulty booster? I had the feeling the tech at MPB was guessing. He said that seals can dry out with light use.

- I paid (at a discount) nearly double for a replacement - (for what I am seeing a 7" dual diaphragm brake booster go for online at Speedway, etc,). Does anyone know if these are US made? or...

- Is this just a standard GM 7" dual diaphragm booster? Could I have just gone down to NAPA or wherever? I'm not sure what I am paying a premium price for here….plus waiting…

BTW, for now, I have a clamp on the vacuum line and have done some careful country road driving this way. With this Mickey Mouse setup, I have just enough pedal to stop with some planning...kind of like the old Huck brakes!