i have an 87 iroc-z and the red brake lamp on my dash is stuck on even when the parking brake is not engaged, what is the best way to go about finding the problem that is causing this? thanks for your help

 

Brake light can come on for 3 reasons:

1) E brake engaged
2) low brake fluid
3) issue with pressure in fluid between front brakes and rear brakes (ie bad proportioning valve or a clogged line).

 

What Jeff stated was all correct and the most likely candidates for your problem. Another two I would add is a faulty spring mechanism sensor that lies within your center console. There is a tiny piece that non-conductive material that separates the metal to metal contact. If that is not fully there anymore OR more likely the spring is not returning to its orig position, metal to metal contact is occurrring and keeping your brake light on despite where the actual position of the ebrake is.

Get the console out and you'll see it. Pull the handle up and down with it out and see if it appears to function correctly. But do his #1-3 first before messing and getting the console out.

 

If you pull the connector of the proportioning valve (removes a ground), and the light goes out, then your problem is most likely #2 or #3 above. If it stays on, then most likely associated with #1 above.

 

Here's a bit more info from the manual:

"The pressure differential warning switch is designed to constantly compare front and rear brake pressure from the master cylinder and energize the warning light on the dash in the event of a front or rear system failure. The valve and switch are so designed that the switch will latch in the "warning" position once a failure has occurred. The only way the light can be turned off is to repair the failure and apply a pedal force to develop approximately 450 psi line pressure."

JamesC

 

ok cool im going to have to check all of this stuff out, thanks for the help its much appreciated

 

Just one more thing. Mine occasionally does this but also none of the accesories or gauges other than speedo work when the tumbler doesn't turn back all the way. The engine runs but nothing else electrical works. I just have to turn the tumbler all the way to run.

 

my cars brake light is also stuck on. I pulled the connector on the prop valve and the light went out. if i stand on the brakes, when I let off the light will go out and then come right back on, basically just flashes off. one thing i do know is that the car was originally a rear drum car, and is now a rear disk. if the prop valve was not changed, ie still has a drum prop valve would it cause this?

 

No. Though for best brake performance, I'd recommend the correct valve (or an adjustable one).

JamesC

 

i guess another good question would be, how do I know what one i have?

 

i was having the same problem. i took off the center console and unplugged the connector, the light was still on. so i went to the message board and looked around. i found this thread. so, i went and un-did the proportioning valve connector and the light is off. my brake fluid level is good. so now what? would bleeding the brakes be worth anything? how can i tell if the valve is bad or if a line is clogged? thanks.

also, i tried really pressing the pedal hard and releasing a few times, and the light does not even flash off, as hubes' did. if that helps. thanks again

 

I also have the light on. My brakes will sometimes act as if they are going to fail. the pedal will drop pretty low to the floor. The red light is horrible to look at. i wish i could find a solution!