Yesterday the brake light on my ’78 started coming on intermittently. By the time I got home it was on solid and has stayed that way. I checked the fluid level and it was fine, but the fluid itself looked burnt. It was black. I bled the brakes last June and I thought I had flushed a lot of the old fluid out.

The Brakes are still working fine. Shoes, and front calapers were replaced last summer.

Is this still old fluid,could something be burning the fluid, or should I be looking for something else?
:confused:

 

Lonnie,


Don't know about a '78, but on my car ('74) the brake light just comes on when the emergency brake is engaged. Sometimes the manual switch connection in the console (under the emergency brake lever) acts up.
You say the brake fluid "looks burnt." Unless it smells burnt and you are having brake problems, I wouldn't worry about it. The fluid in my resorvoir doesn't look too great either. Regards


'74 Turbocharged 350 "Molested to Perfection," class of '71

 

Hey Lonnie, I had the same problem with my 77' and I did some reading in the owners manual and also in the Haynes manual. According to these sources there is a value that regualates the pressure of the brake system. When the pressure is lost the value opens which in turn makes the "BRAKE" light come on. Again according to these manuals the only way to get the light to go off is to restore any loss of pressure or leaks in the system and then to apply "heavy" pressure to the brake pedal. This is what I've read, I'm no expert so if I'm way off will someone please set me straight? Hope this info helps and good luck!

77' L-82, 4spd :cool:

 

Sean, I believe you are speaking of the proportioning valve. You are correct, fix whatever is causing the loss of pressure, bleed, and apply heavy force to the brake pedal. The light will go off. For what its worth, I've heard that valve can be a major PITA to replace.

I also think he should check the parking brake switch. The parking brake handle in my 79 will not always go all the way down, and this causes the brake light to stay on until I monkey the handle enough to get it to go all the way down.

 

hey guys, just kind of a scary thought... what about a hose failing? :eek: figure in round terms those rubber hoses are a quarter century old, not too bad for you and me but a rubber hose that flexes and bends and gets really hot.... just a thought. maybe it's just my paranoid mentality but i would get a helper, drive the car and get the brakes kind of warm (you might want to pick a secluded place just in case i'm right), then inspect all the rubber hoses while your helper keeps the pressure on the binders. for a stretching hose, there would be no fluid loss untill the hose ruptured but enough expansion would create a significant pressure differential between the two sides. (i ran into a similar problem when i put my proportioning valve in mine. i had too little pressure to the rear and it would set off the light since so much more pressure was on the front. once everything got adjusted that all went away). i would also check the e-brake light just to be sure, just disconnected mine the other day (might as well, no e-brake). now, i abuse my brakes so i'm not really a good reference (autocrosser), but i drain and refill my brake fluid every year. c-3 brakes just have to be maitained like that.

 

Thanks for the input. Unfortunately it seems that the previous owner removed the parking brake switch:mad , but the plug could be shorting against the console. So it looks like I'll be getting greasy this weekend. :cheers:


[Modified by LonnieH, 4:25 PM 1/18/2002]