Power brake vacum booster issues
Thread Starter
Drifting
Joined: Nov 1999
Posts: 1,324
Likes: 18
From: St. Peters MO
Power brake vacum booster issues
1996 Vette with only 40,000 miles, heavily autocrossed...( some would say "abused")
Original brake booster went out in Sept. 2011 (cracked plastic case near exhaust manifold), replaced with an "A1 Cardone" re-man. unit with lifetime warranty, worked great till June 2012, replaced for free under warranty, this one worked great for 4 runs at an autocross, then lost boost / vacum. Replaced again under warranty for free, just installed, works great, going to track day and autocross this weekend. They will refund my money if this one fails.
So 2 units gone bad in very short time. Crossing fingers on 3rd.
Any other reason these would be going bad? I know autocrossing is real hard on brake system. Master cylinder was replaced in 2011, and does not leak. (internal or external) Fluid always changed completely.
Just searching for idea's. Or, just bad luck on first 2 units?
BTW: I can now R & R a brake booster in a C4 in under 45 minutes
Original brake booster went out in Sept. 2011 (cracked plastic case near exhaust manifold), replaced with an "A1 Cardone" re-man. unit with lifetime warranty, worked great till June 2012, replaced for free under warranty, this one worked great for 4 runs at an autocross, then lost boost / vacum. Replaced again under warranty for free, just installed, works great, going to track day and autocross this weekend. They will refund my money if this one fails.
So 2 units gone bad in very short time. Crossing fingers on 3rd.
Any other reason these would be going bad? I know autocrossing is real hard on brake system. Master cylinder was replaced in 2011, and does not leak. (internal or external) Fluid always changed completely.
Just searching for idea's. Or, just bad luck on first 2 units?
BTW: I can now R & R a brake booster in a C4 in under 45 minutes
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I have heard of cracking the case caused by headers which bake the case.
I don't know what causes the diaphragms to split. My car has been idling rough for about a month and then the pedal got very hard a few days ago. I think the diaphragm had a small tear and finally blew out when I started the car.
I fixed it about 15 years ago by replacing just the diaphragm. I don't know if you can still buy one separately. When I was under the car about a month ago I saw that part of the booster case was melted by the fire I had. I figured it was only a matter of time before something failed. New booster should arrive tomorrow.
I don't know what causes the diaphragms to split. My car has been idling rough for about a month and then the pedal got very hard a few days ago. I think the diaphragm had a small tear and finally blew out when I started the car.
I fixed it about 15 years ago by replacing just the diaphragm. I don't know if you can still buy one separately. When I was under the car about a month ago I saw that part of the booster case was melted by the fire I had. I figured it was only a matter of time before something failed. New booster should arrive tomorrow.
Thread Starter
Drifting
Joined: Nov 1999
Posts: 1,324
Likes: 18
From: St. Peters MO
I've had 1 with the case crack problem, but 2 with internal diaphragm crack / split / tear in a very short time period.
When that happens, brake pedal gets real hard real quick! and engine at idle runs "off", or "strange" when you apply the brakes at idle. (obvious vacuum leak). Sometimes a louder than normal "hiss" can be heard from under the dash at brake pedal to firewall location.
hoping it was just 2 bad units in a row.
When that happens, brake pedal gets real hard real quick! and engine at idle runs "off", or "strange" when you apply the brakes at idle. (obvious vacuum leak). Sometimes a louder than normal "hiss" can be heard from under the dash at brake pedal to firewall location.
hoping it was just 2 bad units in a row.
Safety Car
Joined: Sep 2010
Posts: 3,752
Likes: 190
From: Indiana PA
The factory GM one lasted how long? Many years, decades under heavy use. The A1 Cardone was didn't last because they are cheap, plain and simple. It is hard to find a quality product anymore. 
I would not call auto-x heavy abuse. Its using the car. As long as you maintain it properly as race car going above any beyond "normal" maintenance, it is not abuse. I keep mine in tip top shape, use the best fluids, and change them frequently. If something breaks I try to buy the best stuff out their without breaking the bank. Often times that means forgoing parts stores and Corvette vendors. Gotta find the specialty crowd.
Its a sports car, what the heck don't people under stand about the "sports" part. You can show boat and cruise around in anything. Hauling @** and taking names while looking good is what Corvettes are about in my book.
I'm really starting to dislike the Zaino car show wanna be crowd. Posers.
Race On!!!
I would not call auto-x heavy abuse. Its using the car. As long as you maintain it properly as race car going above any beyond "normal" maintenance, it is not abuse. I keep mine in tip top shape, use the best fluids, and change them frequently. If something breaks I try to buy the best stuff out their without breaking the bank. Often times that means forgoing parts stores and Corvette vendors. Gotta find the specialty crowd.
Its a sports car, what the heck don't people under stand about the "sports" part. You can show boat and cruise around in anything. Hauling @** and taking names while looking good is what Corvettes are about in my book.
I'm really starting to dislike the Zaino car show wanna be crowd. Posers.
Race On!!!
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I ordered a AC Delco booster through Amazon for $302. The USPS web site says it was delivered, but I haven't seen it. Hopefully it's at the post office.
I autocrossed my car from 1986 until 2002 (when I got a C5). The only problem I had was boiling brake fluid. Fixed that with Castrol SRS -- never had a problem after that. This car is my daily driver now.
I do use Zaino on the C5. Nice stuff. The '86 gets NuFinish. Also nice stuff. I like that it's a cleaner-wax with a little polishing compound in it.
I autocrossed my car from 1986 until 2002 (when I got a C5). The only problem I had was boiling brake fluid. Fixed that with Castrol SRS -- never had a problem after that. This car is my daily driver now.
I do use Zaino on the C5. Nice stuff. The '86 gets NuFinish. Also nice stuff. I like that it's a cleaner-wax with a little polishing compound in it.
