vacuum leak under dash-engine stalls

[livesanuk]

77 spider stalls at low revs. I can hear a leak under the dash. When I depress the brake pedal the sound stops and the idle returns to normal but soon as I let off, the engine will sputter and die. This is my first spider and I'm fairly new at auto repair. My searches seem to suggest brake booster or perhaps a hose somewhere but I'm not really sure. I'm hoping it's something I can repair myself. Any ideas?

[racydave]

Gotta be the booster. You can remove the hose to the booster, and plug it to see forsure. And the brakes will work with a little more effort. Probably better off replacing the booster...

[TulsaSpider]

Yep it's the booster. There's no vacuum lines under the dash . Mine did the same thing a few weeks back.
Check this thread http://www.fiatspider.com/f08/viewtopic ... 9&t=4397It was a pain getting it out.
The clearances are close, speedo, accelerator cables etc in the way. Another pair of hands would probably help a bit with removal, but I did it by myself no problem. I was tying things out of the way. There's two nuts on the booster/master cyl to remove and four bolts under the dash and the brake pedal connection, that's it! I had mine for about 6 months and it's my first spider too. I didn't realize my booster wasn't working the entire time. Now it stops better than ever! If you are poor like me you might try to find a used one, cause the new ones are pricey!! Also when I was at my first Fiat meet I had just done the booster a day before. I was discussing this with the leader of the group and he said many times that there is a rubber washer that begins leaking. He said to simply turn that rubber washer over and it would seal again. However like I said before mine wasn't working before so my main diaphram was torn and that is not serviceable. So if this is not your main transportation you might try that. You'd still have to take the booster out. if possible I'd suggest getting a new one, everyone's situation isn't the same after all!
Good luck!