The parking brake light in the dash that says "brake" in my 97 Legacy has been intermittently going on and off for some time now. I read in other threads that low brake fluid could cause this but the fluid is full. The front brakes are new last summer, a large amount of the fluid was drained/replaced, and the light will go on off regardless of temp and driving time. Seems totally random.

When I started the car and put the brake down the other day the light went off with the parking brake lever going down as it should and then went back on when I pulled the parking brake lever up later. I'm thinking it might be the sensor (if there is one). Does anyone know where the parking brake sensor is and if it can be cleaned, repaired, replaced or disabled? I am probably trading in for new Impreza soon and trying to get the car tuned up so they don't nickel and dime me to death.

 

Thanks

Edited August 31, 201213 yr by Nbe1210

It has two jobs. One is a plain ol switch in the PB, another is a switch in the cap of the brake master cylinder. The light tells you when the brake is on, and when the fluid is low. It is so rare to have a major brake line failure these days they monitor the fluid level. Old switches would come on when you pressed the brake pedal, and by then you did not need a light to tell you you were in trouble.

 

Make completly sure that the hyd's are ok and the pads/shoes are good. Once you have confirmed that, It may be the switch in the cap. I don't think there is a line balance switch anywhere.

 

Another possability, beleive it or not. is the Alt is dying. When the alt goes bad the brake light indicator is one of those things to come on. Check your charging system and clean the battery terminals. Check alt output at 1800 RPM and everything on.

I had a similar problem for quite some time. Everything was good and the reservoir was full, no problem with the parking brake sensor. If I wanted full braking power as soon as I hit the brake I had to push the pedal down a bit coming up to a stop. After 3 or so months of this my pedal went straight to the floor. Switched the master brake cylinder and it was fixed.

the switch for the parking brake is located under the center console on the passenger side. it is a simple switch, compressed is off and extended is on.

 

 

you could try jumping it out so the hand brake lever does not turn on the brake light and see if you have any funny issues after. if no then replace it. but if you could swap in a known good used switch for a few $ that might be good too.

If you simply unplug the switch the light won't work with the parking brake. Incomplete circuit = no light.

I read in another thread that the rubber piece on the bottom of the brake fluid cap needs to be pushed In so it is concave. It worked and the light has been off for a few weeks now. It took about 1 minute. Thanks for all the suggestions, my next project is the o2 sensors since the check engine light is on.

I read in another thread that the rubber piece on the bottom of the brake fluid cap needs to be pushed In so it is concave.

 

the rubber diaphragm under the cap extends as the fluid level drops.

the fluid level drops as the brake pads wear and the caliper piston has to extend farther to do the job.

 

so if the brake system does not leak, you can correct the ''brake'' light on usually by adding brake fluid. BUT BUT BUT when you replace the pads, and compress the caliper piston, the fluid MAY over flow the reservoir.

I replaced the front pads, rotors and calipers this past summer but did not know about the diaphragm until recently. Pushing it back in seems to have solved the problem as the light is still off and has been for a while. The fluid has been steady and full since the service this past summer. Thanks for the info.