Spongy Brakes in '95 PA

[bulldog5]

Have a '95 PA that the brakes "went out". Replaced the M/C bench bleeding and it worked for about 2 weeks. Then we replaced the M/C again with another new one thinking we had a bad one. Same thing - - - brakes for about 2 weeks. Then we re-bench bled the M/C and did a complete pressure bleed on all wheels. Had brakes then for about 5 to 6 weeks.
Now they have failed again. No leaks; no loss of fluid whatsoever.

We recently pulled the lines and vacuum tested the lines and all was ok. On the ABS pump where it is supplied by 2 lines from the M/C, one port holds a vacuum great but the other does not. Is this a valid test?

Any thoughts or advice here would be GREATLY appreciated.

Thanks.
bulldog5

[Cntrysthbst]

If it was me having these problems, which I normally do, I would take it to a pro., maybe even the dealer. I would try a brake shop first, one who offers a warranty on there parts AND LABOR, that way if it does happen again...your covered. Sorry I could not help more. Am interested in what you find out.

[Wrightjsjj]

I had the same problem with my '93 PA. Went through two MC's from Autozone, then took it to my local mechanic who installed a Bendix MC. That one lasted about six months then went bad again. This time I sucked it up and took it to the dealer who installed a factory part (Delco.) It's been working great for a year and a half now.