Got brakes......
Thread Starter
2nd Gear
Joined: Oct 2007
Posts: 2
Likes: 0
Got brakes......
I have a 1994 corvette that I purchased for street/track events (Auto-X). At my last event (auto-x) I developed a progressive problem with the brakes. As the day went on, the brakes or pedal began to at first became spongy and by my forth /fifth run the pedal traveled almost completely to the floor with almost complete brake failure!
I am the 3RD owner and believe most of the braking system/components are original except I have purged the complete system and filled with Valvoline synthetic dot 4 fluid. New Hawk HP Plus pads, turned the rotors and bedded them in correctly. There are no obvious leaks and the systems was done (purged) in service at the GM dealership where I work. There is another C4 1991 Corvette owner and he states that he is experiencing th same problem The question is has anybody else had this problem and any suggestions on how to solve this issue? By the way, I`m racing in "A Stock SCCA"
I am the 3RD owner and believe most of the braking system/components are original except I have purged the complete system and filled with Valvoline synthetic dot 4 fluid. New Hawk HP Plus pads, turned the rotors and bedded them in correctly. There are no obvious leaks and the systems was done (purged) in service at the GM dealership where I work. There is another C4 1991 Corvette owner and he states that he is experiencing th same problem The question is has anybody else had this problem and any suggestions on how to solve this issue? By the way, I`m racing in "A Stock SCCA"
Safety Car
Joined: Dec 2006
Posts: 4,290
Likes: 6
From: St Marys GA
If you're using it for racing, I would get some NACA ducts and silicone tubing to cool the front brakes. Mid-America and other such places sell replacement air-deflectors with these built-in, but the hoses are crap, so you might as well build your own.
Also, does your 94 have the J55 HD brakes? I forget when they came standard, 94 or 95. If you don't have them, you may want to do that as a cheap brake upgrade. The standard front brakes are 12", the J55 are 13", so it's pretty easy to tell. You can pick up a set of J55 rotors, calipers and mounting brackets here for pretty cheap if you time it right.
Also, does your 94 have the J55 HD brakes? I forget when they came standard, 94 or 95. If you don't have them, you may want to do that as a cheap brake upgrade. The standard front brakes are 12", the J55 are 13", so it's pretty easy to tell. You can pick up a set of J55 rotors, calipers and mounting brackets here for pretty cheap if you time it right.
Melting Slicks
Joined: Apr 2004
Posts: 2,775
Likes: 138
From: cyberspace NY
It's the Valvoline synthetic dot 4 fluid. I had the same problem until I switched it to Castrol LMA. They even took that fluid off the market.
Expecially at auto-x, where you should never have fluid problems. 60 seconds of running your car should do nothing to brakes. maybe you use the brake 10 seconds out of 60.
oh, your not racing. your simply driving through cones.
and maybe the GM super mechanic didn't purge anything, which is more than likely, unless you watched him.
get 2 containers of castrol LMA, and WATCH the guy flush the entire system, wheel by wheel, even if you have to stand there.
Expecially at auto-x, where you should never have fluid problems. 60 seconds of running your car should do nothing to brakes. maybe you use the brake 10 seconds out of 60.
oh, your not racing. your simply driving through cones.
and maybe the GM super mechanic didn't purge anything, which is more than likely, unless you watched him.
get 2 containers of castrol LMA, and WATCH the guy flush the entire system, wheel by wheel, even if you have to stand there.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
What method did the tech use to "purge" the system? Sometimes a tech will get "lazy" and use a gravity bleed method. While it might work for some cars, it's always a good idea to use a pressure tank or have two people bleed the brakes, One person opens and closes the bleed screw while another person in the car pushes on the brake pedal.
If the dealership did in fact flush the system the master cylinder reservoir should have clean and clear fluid in it. Does it?
Bleeding your own brakes is easy to do especially if you install Speed Bleeders Using these makes it a one person job and you can do an entire flush in about a half-hour at home.
Another good item to use is the Motive bleeder. It's a small plastic tanks that you can either fill with fluid or simply pressurize and use the air pressure to force fresh fluid through the system.
If the dealership did in fact flush the system the master cylinder reservoir should have clean and clear fluid in it. Does it?
Bleeding your own brakes is easy to do especially if you install Speed Bleeders Using these makes it a one person job and you can do an entire flush in about a half-hour at home.
Another good item to use is the Motive bleeder. It's a small plastic tanks that you can either fill with fluid or simply pressurize and use the air pressure to force fresh fluid through the system.
