Brakes spongy again a week after bleeding

[cferb]

Any ideas? They were spongy already, still stops but the pedal goes far down, bleeding it got it back to normal but then it went back to being spongy after about a week of driving. 91 318i if that matters.

[Dakotademon7]

It may be a master cylinder going bad. If you pull it and there fluid behind it,it's going bad. Also. Heck the brake calipers for leaking seals.

[cferb]

Oh, I should also note it's not leaking any fluid at all.

[Dakotademon7]

You won't really notice a leak from a bad master cylinder. The fluid is trapped between the master cylinder and brake vacume booster. In most cases, you can just undo the two mounting bolts and separate it just a little to check. If you see any fluid run down the face of the booster then you know its bad. I would also check every inch of all your brake lines for any wet spots.

[cferb]

You won't really notice a leak from a bad master cylinder. The fluid is trapped between the master cylinder and brake vacume booster. In most cases, you can just undo the two mounting bolts and separate it just a little to check. If you see any fluid run down the face of the booster then you know its bad. I would also check every inch of all your brake lines for any wet spots.

Cool thanks, something to look for when I check it out in a minute here.

[cferb]

Well I didn't take that apart, but there's a vacuum hose going into the booster that looks to be leaking air, the piece plastic elbow fits loosely into a worn out gasket, I'm thinking that may be it, does that sound plausible?

[Dakotademon7]

Low vacuum to your power brake booster will make your brakes feel stiffer when braking. It will feel more like non power brakes.