[BORKAT]

OK, after the PA Saab meet and all that "spirited driving" last weekend my brakes were shot. I was getting fade and the peddle would drop to the floor at lights. No big mystery there. But now the peddle is stiff. It will only move a tiny bit. That still don't stop me very well, it's just stiff. And when I have the brake depressed it makes the car idle lower! Any ideas?

 

[Tweek's Turbos]

Maybe it shook something loose in the lines, do a bleed and see if that helps.

 

[DeLorean]

either a vacuum leak at or before the brake booster or a faulty brake booster. about a $10 part at the junk yards if the booster has had it.

 

[BORKAT]

OK I'll throw out every detail I can think off. Sunday a bunch of us from saablink and saabcentral had a meet/run. (I just got banned from saabnet for saying that) My brakes here getting beat to hell and back. You could smell them burning and there was a lot of fade. Lucky for me Delorean was in front and had no brakes either. Then I took this one turn really hard at the end of the day. It was a right. Not a curve, a right turn at about 35. Anyway, after that I heard a grinding that got worse when I put on the brakes. After a bit, it went away though. So the next few days I dive the car and the peddle is fading on me. No big deal, I got another bad part from Burnside I assume. And the master cylinder he said he rebuilt was bad. I want my $6.00 back! But the third day I drove it to work, had the brake depressed and shut off the car. The peddle pushed back up. It's been stuck up and stiff like somebody slipped Viagra in my brake fluid since. That's also when the rpm dropping started. That's everything.

 

[c900]

either a vacuum leak at or before the brake booster or a faulty brake booster. about a $10 part at the junk yards if the booster has had it.

I agree with this as a possible cause. When you have to use excessive force to apply the brakes it'll almost always be the brake booster or loss of vacuum into the booster. Check it's getting vacuum from the intake manifold, and ensure the vacuum supply isn't leaking. They can also leak around the seal for the shaft which pushes on the pistons on the brake master cylinder.

Replacement boosters are very expensive to buy new, but cheap from wreckers, etc. I did a brake master cylinder replacement on my 1985 900i some months back which might help give you some tips on working out what the problem is.

Regards,

Craig.