'90 Vacuum Booster Leaking?
Thread Starter
Instructor
Joined: Aug 2002
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From: Saint joseph MI
'90 Vacuum Booster Leaking?
I've recently bought a '90, 6spd roadster (best performance bargain out there!). I can hear what sounds like a vacuum leak under the drivers side dash. It goes away upon acceleration or applying the brake. At first I assumed the vacuum booster was leaking, but the brakes work fine. Is this noise unusual, or are their other vacuum lines under this part of the dash? Or is it the booster? Thanks in advance.
Jeff
Jeff
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From: SE NY
Cruise-In II Veteran
Re: '90 Vacuum Booster Leaking? (jhughes2101)
Vacuum lines feed through the firewall next to the booster to power the climate controls.
You could plug that feed in the engine compartment to see if the leak is under the dash.
You could plug that feed in the engine compartment to see if the leak is under the dash.
Thread Starter
Instructor
Joined: Aug 2002
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From: Saint joseph MI
Re: '90 Vacuum Booster Leaking? (65Z01)
Thanks, I'll trace down the vacuum lines for the A/C tomorrow and try pinching them off. I also was going to disconnect and plug the vacuum line to the booster and see if the noise goes away. I findit hard to believe withthe noise I"m hearing, that if it was the booster, it would be working at all!
Melting Slicks
Joined: Jan 2001
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From: MOORESVILLE NC
Re: '90 Vacuum Booster Leaking? (jhughes2101)
I had the same problem with my 76 and 88. Yes the brakes still worked with slight more peddle effort, more noticable on the 88 due to ABS. You can do the brake boster yourself. Unhook the master cylinder bolts at the boster first. then ( this is the fun part) get your head under the dash and you will see 2 bolts the same size near the top of the brake pedel on the inside fire wall. Remove these and your boster will pull. If you are a tall or big person you might want to remove the seat ( 4 bolts and some wire plugs) which is not difficult at all. use a small screw driver to remove the wire plugs. After all these years the plastic is more brittle.
Thread Starter
Instructor
Joined: Aug 2002
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From: Saint joseph MI
Re: '90 Vacuum Booster Leaking? (jhughes2101)
Thanks all for the advice. Well, I plugged the vacuum line to the booster and sure enough, the hissing went away inside the car. I assume this means booster input rod seal has gone bad (since I can't hear any hissing underhood). Can I rebuild the booster or should I just get a new one? If I can rebuild, where do I get parts?
Jeff
Jeff
