Remanufactured Booster Problems

[wildstoats]

Hey guys, I just put a new MC and Booster on my '91 318 and the booster is hissing like crazy. Very loud vacuum leak from inside the engine compartment. If I disconnect the vacuum hose from the booster and put my thumb over it the sound goes away so that seems to point to a booster issue. I also noticed that when I press down on the brakes the noise goes away which seems odd to me.

When I swapped everything over I made sure to install the new o-ring between the MC and Booster but other than that I can't really see anywhere else the thing could be leaking from except perhaps internally. Did I just get a bad one?

[jlevie]

Sounds like a bad booster.

[wildstoats]

Yeah, suppose it happens.

[AndrewBird]

Are you sure you have the brake pedal clevis adjusted correctly? If it doesn't have a bit of play, it can cause the brakes to be on slightly and the booster will hiss. It will also slowly lock your brakes on.

[wildstoats]

Yeah, I believe Bentley says 4.92" that's where I set it anyway. I don't think I missed anything just screw/unscrew the clevis, lock the nut and you're done right?