brake warning light

[chadwick88]

Help....need someone's advice when it comes to brakes on a 79 L-82 (stick). Recently my brake warning light stays on without ever going off while driving. At first I thought it was my emergency brake handle not being pushed down all the way, but after playing with that for awhile it still was on. I have noticed when appling the brakes it is requiring more pressure on the pedal to stop the car (not much more, but more ). I have no leaks, and the cyllinder is full of fluid. The vacuum from the booster to the intake manifold is strong, so I am not losing any pressure there. I had my brakes checked about 3 month ago when I had new tires put on, and they were fine. I am not feeling any tugging or pulling to one side or the other when apppling the brake, or any noise from the brakes as well. My next step is to bleed the lines if needed, but thought I would shoot this out to the group first, anybody ever have this problem before???...I can tell you my emergency brake's do not work that well, hardly at all in fact...would this be the reason the brake light goes on, if so why???.... thanks in advance for your help....

 

[MaineShark]

I think your "next step" is the correct one. I had similar problems a while back, and that was the advice that I got. Worked like a charm.

Joe

 

[Bob Chadwick]

Same problem on my 77. Bleeding the brakes took car of it.

 

[chadwick88]

thanks guy's, bleeding the brakes it will be!!!!!!!!!!!!!!!..

 

[cruisin-davey-g]

Help....need someone's advice when it comes to brakes on a 79 L-82 (stick). Recently my brake warning light stays on without ever going off while driving. At first I thought it was my emergency brake handle not being pushed down all the way, but after playing with that for awhile it still was on. I have noticed when appling the brakes it is requiring more pressure on the pedal to stop the car (not much more, but more ). I have no leaks, and the cyllinder is full of fluid. The vacuum from the booster to the intake manifold is strong, so I am not losing any pressure there. I had my brakes checked about 3 month ago when I had new tires put on, and they were fine. I am not feeling any tugging or pulling to one side or the other when apppling the brake, or any noise from the brakes as well. My next step is to bleed the lines if needed, but thought I would shoot this out to the group first, anybody ever have this problem before???...I can tell you my emergency brake's do not work that well, hardly at all in fact...would this be the reason the brake light goes on, if so why???.... thanks in advance for your help....

You mention that it takes more effort (pressure) to push the pedal down in order to stop? Or is the pedal traveling more (distance wise) in order for your vette to stop?

Dave:confused

 

[Vette/Berlina-coupe]

Hello Chadwick: -You've got it, the C3/Emergency/Parking-brake is in a word" "absurd" -if dangerous (look at it, --the integral-drum is a dinky lil'thing; --some sort of hi-friction shoe improvement is needed); --but you're fortunate to have stick-shift, so at least you have the option of positively downshifting in many dire situations, -where an automatic is if'ie... ~Bob vH

After-thought: -maybe someone could experiment with drilling lots of say 1/4"Radial-holes (try initially on obliquely-staggard 5/8"-centers) in the brake-drum's surface, in order to thereby effectively increase the binding-friction of the brake-shoes! One would naturally preferably use two C3-Vettes of same weight and identical brake-shoes for comparison, -thus first testing both for braking comparison prior to the perforation-modification at different speeds(shooting video to document the results before/after)! This notion would be somewhat akin to the racers now popular cross-drilling of the disk-brake Rotors, as to attain greater friction and enhanced cooling-ventilation. -If this concept significantly improves performance as seemingly predictable, these notorious C3/Emergency-brake drums could be made to actually slide one's rear-tires(or even hold on a hill pray tell), particularly useful in emergency situations when the Hydraulic-disks have taken leave (as has happened to so many of us without warning)....
~Bob VonHeck

note: -thought worthy to post this concept as an independent topic of the forum, so please respond to it there.

 

[Ala75Vette]

By now you've probably already done it, but bleeding the brakes on my '75 (plus adding more fluid to the master cylinder) got my brakes back in business when my brake light came on. In my case, the front calipers were shot, so I wound up replacing them as the 'long term' fix.

 

[JohnZ]

Air in one half of the system will cause a pressure differential, which causes the light to go on (differential pressure switch internal to the distribution block below the master cylinder). If bleeding it fixes the problem and it comes back again, you need to find out where the air is coming from - chances are it's due to excessive lateral runout in the rear rotors causing "air-pumping" past the seals in the rear calipers, which can also be caused by rear wheel bearings that are worn beyond spec.

 

[chadwick88]

thanks for everyone's input, I am bleeding the brakes tomorrow night and will keep everyone updated if this does the trick or not.....

 

[Gunther]

Hi
Didn't you say that the brake light is on all the time, even without pushing the pedal ?
If this is so, just bleeding will not fix it.
You need to reset the light switch. So after you bled the system and the light stays on, you need to firmly push the prake pedal to reset this switch. Check the CHILTON's manual for the procedure.
Let us know how it works out.
Gunther

 

[stingray4me]

Oh yeah C-3's & brake problems go together like peanut butter & jelly. I have to bleed my front brakes about every 3 months. Even replacing the rotors & the calipers with ss ones & repacing the master cylinder several times didn't help. The brake light goes to the proportion valve located about a foot from the master cylinder for your info. I also replace the emergency brake workings completely too. One thing I never replaced was the booster though. The 75 has about 178,000 miles on it.