BRAKE LIGHT STAYS ON HELP !

[Nobody Cares]

The brake light had been staying on for a couple of weeks. 1980 vette. Brake pedal was getting a little spongy. I changed the master cylinder today and bleed all the lines. Brakes are working great now. But the brake light between the speedo and tach stays on. I pulled the tan and white wire off the brake porportioning valve and the brake light went out. I tested the wire with a tester at the pug (where it plugs into the porportioning valve ) and there is power there all the time. I plugged it back in the porportioning vavle and the brake light stays on. Can anyone give some ideas what to do or check. THnx Dave

[gmjunkie]

Originally Posted by Nobody Cares

The brake light had been staying on for a couple of weeks. 1980 vette. Brake pedal was getting a little spongy. I changed the master cylinder today and bleed all the lines. Brakes are working great now. But the brake light between the speedo and tach stays on. I pulled the tan and white wire off the brake porportioning valve and the brake light went out. I tested the wire with a tester at the pug (where it plugs into the porportioning valve ) and there is power there all the time. I plugged it back in the porportioning vavle and the brake light stays on. Can anyone give some ideas what to do or check. THnx Dave

How did you bleed the brakes?? RR,LR,RF,LF?? Proportioning valve may be stuck!!

[Nobody Cares]

Front first then the rear. Any ideas if the porportioning valve is stuck. Get out the hammer ???? Dave

[gmjunkie]

Originally Posted by Nobody Cares

Front first then the rear. Any ideas if the porportioning valve is stuck. Get out the hammer ???? Dave

Try starting at the right rear to left rear to right front to left front!!! 3 squirts RR,3 squirts LR, 3 squirts RF, 3 squirts LF and see if that don't help!! PS some proportioning valves has a rubber cap on each end and you can center them by hand!!

[22229stingray81]

Isn't there a way of resetting the brake "system" but pressing down HARD on the brake pedal for a few seconds? Perhaps try that and see if it goes out.


-Tatortot

[DarkShark]

Originally Posted by Nobody Cares

The brake light had been staying on for a couple of weeks. 1980 vette. Brake pedal was getting a little spongy. I changed the master cylinder today and bleed all the lines. Brakes are working great now. But the brake light between the speedo and tach stays on. I pulled the tan and white wire off the brake porportioning valve and the brake light went out. I tested the wire with a tester at the pug (where it plugs into the porportioning valve ) and there is power there all the time. I plugged it back in the porportioning vavle and the brake light stays on. Can anyone give some ideas what to do or check. THnx Dave

Did you check for a bad connection at the e-brake switch? If I remember correctly, this little connection will trip the light on the dash too.

I have the same issue- I think it is a short in the parking brake switch because I know my proportioning valve is fine.

[GerryLP]

Originally Posted by 22229stingray81

Isn't there a way of resetting the brake "system" but pressing down HARD on the brake pedal for a few seconds? Perhaps try that and see if it goes out.


-Tatortot

You are correct, Tatortot!

When there is a an uneven pressure on the proportioning valve, this will set the brake warning light, and to reset it, one has to correct the brake problem, bleed the system, and then press hard on the pedal to reset the balanced pressure and that will extinguish the light.

[22229stingray81]

Originally Posted by GerryLP

You are correct, Tatortot!

I usually am, Gerry!

[Nobody Cares]

No luck so far fellas. Pressed HARD on the brake pedal , but light is still on. Took the car out for a ride early this morning , light still on ???

[Nobody Cares]

Anyone know if the should be power at the emergency brake switch ?? I pulled the wire off at the emergency brake switch , and had no power with the test light. ?? The only way so far that i been able to get the dash brake light to go out is pull the wire at the porportioning valve. Dave

[wishuwerehere82]

Originally Posted by Nobody Cares

No luck so far fellas. Pressed HARD on the brake pedal , but light is still on. Took the car out for a ride early this morning , light still on ???

Usually just pressing hard on the pedal doesn't do it.
A couple of good hard stomps or stabs on the pedal will.
The idea is to get the fluid flowing fast and under pressure through the switch body to dislodge the piston from the cylinder.

[gmjunkie]

Originally Posted by Nobody Cares

Anyone know if the should be power at the emergency brake switch ?? I pulled the wire off at the emergency brake switch , and had no power with the test light. ?? The only way so far that i been able to get the dash brake light to go out is pull the wire at the porportioning valve. Dave

There won't be if the light is on,the light has already been grounded!!! If you unplug the proportioning valve,then there should be power!! the single wire to the valve and emergency brake are nothing more than a ground for the light that gets a Ground and turns on the light!!!Re-bleed the brakes starting at the wheel farthest from the Master Cylinder RR and then next farthest LR and then next farthest RF and then Last LF !~! C3's can be a real Bear to get ALL the air out,sometimes you will have to raise the rear of the car as far as possible and "PUMP The Hell OUT OF IT" and Hold solid pressure on the brake peddle!!!!

PS Be sure and bleed Outside of rear calipers First,Inside Second!!

[Nobody Cares]

Ok Thnx, I'll get er dun. Thnx for the info . Dave

[GerryLP]

On the L81, you have to press the pedal hard enough to develop 450 PSI line pressure, and when I did that, the force required to extinguish the light was higher than I thought...perhaps you have to stomp on the pedal as hard as it would be needed to bring the Vette to stop as if you were traveling 65 MPH.

That's how it seemed to me ....

[Nobody Cares]

Ok, I would have thought i had prssed hard enough but will give it another stomp or two. Thnx Dave