hatchdemon89

OK so i took my 89 gt out on sunday for a drive anywayz hit the brakes and it isn't stoppin so great i can hear a air noise really loud when u penetrate the brakes lol i mean its loud in the cabin inside the car checked under the engine bay for a vacum leak nothing so i disconnected the bb vacum line an the noise went away what is the problem should i just buy the brake booster eliminated?

hatchdemon89

ok well im goin to work ill check later

hatchdemon89

wow noone can help me?

Twisted

Doesn't a fat vacuum hose run to a small unit connected to the brake pedal...inside the car? Does it sound like the sound is coming from inside the car or outside?

hatchdemon89

inside

hatchdemon89

its wierd idk anything about brakes but the break pedal is heavy an makes a air compressor air noise an doesn't stop great

Twisted

You may want to stick your head under the dash and have a look. You should be able to see what I'm talking about. I think it's a vacuum bypass unit that the hose goes into--something like that. I can't remember exactly.

turbosha

i think that hose is for the cruise, so when you hit your brakes the cruise kicks off. you probably have a bad booster. disconnect the vac line going to the booster and plug it if you can still here the noise its not the booster.

Luckythirteen

Mine was doing the same thing about a month ago, sounded like an airhose leaking inside the cabin and felt like I was stepping on a brick when I tried to stop.. Turned out the diafram in the brake booster had a hole in it and was toast. Took me about 2 hours to replace it, probably coulda gona faster if I had just removed the master cylinder instead of being subborn and not wanting to bleed my brakes,

hatchdemon89

ok guys i know i keep saying something when this thread is old yea when u disconnect the line in the engine bay for the booster the noise goes away i was told to change black valve on the boster ?im not sure