Brake light issue

90CougXR7

Registered User
I've done a whole heap of searching and yet to find anyoen that has had an issue similar to this. Here goes.

Got a 1990 XR7 with about 65K on it. Lately I have had some issues with the brake light coming on and staying on. Here is how it all works.

In the morning, when I start her up both the ABS and Brake lights come on for a few seconds and then turn off. So I put the car in D and take off. As soon as I have driven a few feet or so the brake light will come on and stay on until I park the car.

After getting to where I need to go, and after the car has warmed up it seems, then the brake light will only come on after I have pressed the brakes. I'll press the brakes, the light goes off and I come to a complete stop with no shuddering, no pulling, no nothing. Everything is smooth as far as braking goes. I press the accelator after coming to a complete stop and the light will come on about a second every single time. It's like clockwork. It will stay on for about a minute maybe less and then turn off until I press the brakes again.

I did notice that if I am on the freeway, and not using the brakes then the light will stay off. But sometimes it will come on after using the brakes, and sometimes it won't.

The brake pads are fine. The rotors are fine. No major wear and nothing that looks like warping. I did unplug the wire at the brake block, forget the name, located on the lower driver's side inside the engine bay to see if that would affect the light. Nothing doing.

I just wanted to know if any of you have had this problem before or not.
 
Low fluid

As odd as it might seem, about the only thing that will cause the Brake indicator to come on intermittently is low fluid level in the reservoir. Be sure to check the level with the system fully charged. The accumulator sucks up a good bit of fluid when the pump builds pressure so if you check after the car has been sitting for a while you may get a false reading. Turn the key to RUN and let the pump charge the system, then check the level. If that's not the problem, you may want to check the wiring and connector for the fluid level sensor on the reservoir cap.
One more thing... You might need to bleed the brakes because air in the lines will compress as the pump runs and this will also suck more fluid from the reservoir causing the level to drop (triggering the sensor).
 
LJGriggs said:
As odd as it might seem, about the only thing that will cause the Brake indicator to come on intermittently is low fluid level in the reservoir. Be sure to check the level with the system fully charged. The accumulator sucks up a good bit of fluid when the pump builds pressure so if you check after the car has been sitting for a while you may get a false reading. Turn the key to RUN and let the pump charge the system, then check the level. If that's not the problem, you may want to check the wiring and connector for the fluid level sensor on the reservoir cap.
One more thing... You might need to bleed the brakes because air in the lines will compress as the pump runs and this will also suck more fluid from the reservoir causing the level to drop (triggering the sensor).

Thanks for the help. That was the problem. I turned the key to RUN and watched as the fluid level dropped. The question now is should I fill her up while the key is on RUN, since I presume that after the key is turned OFF the fluid levels will rise above the arrow mark on the side of the reservoir. Or do I just fill her up while the key is OFF?
 
Don't worry about overfilling the reservoir. The arrow points to the full level with the system (accumulator) fully charged. There should be plenty of expansion room left in the reservoir for the fluid after the accumulator discharges.
BTW, congrats on having one of the few problems that doesn't require removing a dozen parts just to get to the bad one. :D
 
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