1981 Vette Brake Question

[Jeffrey]

I gave my car a little road time today for the first time this year and after driving for about 15 minutes on quiet Bucks County back roads, I noticed that my brake light was lit. I lightly tested the bakes and noticed a huge reduction in braking ability. I was able to brake by slowing down and then pushing the brake pedal to the floor. Got her home, but obviously there is something wrong. All calipers were replaced a few years ago, but I put very, very low mileage on my car. She only has jusy over 6,000 original miles. Any suggestions? Could this just be a brake fluid leak, or might this be a master cylinder problem?

Thank you!

[Frank Gonzalez]

Brake light comes on when there is a difference in pressure between the front and rear brake systems that exceeds a preset limit.

You likely have a fluid leak or a bad master cylinder. Get that puppy to a qualified mechanic right away.

Frank Gonzalez

[Glennm27]

Brake light comes on when there is a difference in pressure between the front and rear brake systems that exceeds a preset limit.

You likely have a fluid leak or a bad master cylinder. Get that puppy to a qualified mechanic right away.

Frank Gonzalez

Qualified Mechanic: aka Steve Spencer, Bryner Chevrolet, Jenkintown, PA

[Keith Pladsen]

Friend of mine had a similar experience and after many, many trips to the dealer finally found a guy like Spence who determined the pistons were essentially "frozen" to a limited travel within the piston liners. He had to replace both the pistons and the liners which were replaced with stainless steel parts as the OEM were rusting causing the poor brake performance.

Not sure this is your issue but figured I would pass along.

[Jeffrey]

Thank you all for your feedback and insight. I am going to have my vette looked at this week because it is never a good idea to drive without good braking power.

Jeff

[frantark10]

Jeff......what was the issue with your brakes in the end? I have a similar situation with my 77.....have replaced master cylinder and front calipers so far......no fluid leaks......can bleed and get good pedal........after a short period of driving.....pedal drops and light comes on...... I could use a little help on this one.
Thanks

[Bob Weiss]

Could be several things:
1) Master cylinder (per Above)
2) Leaking calipers (Per Above)
3) Leaking brake lines (remember-these cars are getting old)
4) Bad seals on calipers (Allows pucks to suck in air if calipers are cast or steel lined and move slowly or are pitted) Hopefully when they were rebuilt you used stainless steel liners. Most people are replacing their pucks with O-ringed pucks that reduce this issue. I think the company that makes these is Precision Engineering??
5) Should not be the Power brake booster as this would make the pedal harder to push if loosing vacuum.
6) Moisture in the brake fluid (Will boil when the brakes get hot).

Just some thoughts.

Bob

[frantark10]

When it was all said and done, it appeared two things contributed......too much runout on the back rotors, and a tiny rear caliper leak which we didn't spot until some brake dust built up in that area.......and the "rebuilt" master cylinder also had a minute leak. Rotors done and trued to within .003", new calipers and shoes, e brake system rebuilt while we were at it, and master cylinder replaced again.......fingers are now crossed with lots of prayers.

[Bob Weiss]

Good Luck !!

[frantark10]

Think we finally have licked the problem........can drive it now without worrying about killing myself or someone else.......yay!

[Bob Weiss]

Sounds good !! Now drive it !!