Did my brake booster just go?

[FL02]

I was cruising, and my brakes started to feel wierd. They felt real tight and mechanical, and when I pressed them the idle would go up. Upon inspection, when I press the brake pedal, I hear a woosh sound of air releasing from the bellows end of the brake booster. Is this a common symptom of a booster going out? I have another booster, but I'll probably change the hoses first. Any help is appreciated.

[Vroomer]

How's your brake fluid level?

[Gil]

It sounds like you have a big vaccuum leak for sure. Are you puffing smoke out your tailpipe now? Sometimes, the o-ring between the booster and master cylinder fails, and you end up sucking air and brake fluid into the engine, which shows up as blue smoke under higher vacccuum conditions (deceleration). A low fluid level in the reservoir would be a clue to this too.

Yes, check the hose to the intake manifold for leaks. These eventually fail and leak. I suppose it could be the booster as the last suspect. You could plug the hose at the intake manifold and see if the engine idles better/properly.

Gil

73 02

[FL02]

I have another booster here, and the fluid if fine. The reason I suspect the booster is because the sound of the air releasing is right at the end near the brake light switch, where it attaches to the upper brake lever. Thanks

[Timmer]

I tend to think it's the diaphragm in the brake booster that has gone bad. The symptoms you described happened to me a couple of years ago in my 1969 2000 and it happened right after putting on new discs, pads, and rear shoes. The hissing noise was plain as day while braking and shuttering as well, the idle also rose when braking. I replaced the booster hose and check valve, still the same. I ended up replacing the booster and that did it. It is the only booster I've replaced out of 8 2002's and 3 NK's.

Tim

'69 2000

[FL02]

probably the booster...thanks

[Timmer]

New ones are about $400.00, Carl Nelson rebuilds them and sells rebuilt ones for $350.00 or so. I bought a good used one for $50.00 from Al Taylor, 2 years ago or so, it was off of a 2000 parts car he had. I believe you won't have to disconnect the metal lines from the master cylinder, just to unbolt that. I had to take the metal lines off of my 1969 2000 brake master cylinder in order to get the booster out and then bleed the system, once the good booster was in.

Tim.

[FL02]

Just finished with the booster install, and it fixed the problem. Getting the steel brake lines to thread right took a while. I had to drain the whole system and take off the booster and master cylinder at the same time as they were both connected by rods. On reassembly, I kept all the bolts loose-finger tight to get the steel lines started. I had another booster, my original, that I replaced when I had to buy a new brake master cylinder. The hissing sound and the idle issue was the power brake booster for future refrence & I'm Glad I had one, what a PITA...I'm starting to know this little car like the back of my hand. I can almost do repairs by feel.

[Timmer]

Yeah, that's really the telltale sign of a bad diaphragm; the hissing sound and high idle/car shuddering while braking. The clevis/pin for the brake booster on my 1969 2000 is inside the car, behind the pedal, very tight getting back in that area. Some folks tell me they can remove the boosters from their 2002's without having to take off the metal lines of the master cylinder once that is unbolted, maybe it depends on the year of the 2002. At least you're all set now. There used to be a local place here that rebuilt boosters but they closed up a few years ago.

Tim

'69 2000