brake help

well you can guess by my username that i have a 1988 buick park ave,
well my brake light has come on and i dont know why. im theorizing a couple things.
theory 1-parking brake
one time i set my parking brake and when i released it, the light was still on, so i put it on all the way and released it and the light went off so i thougt nothing of it. well about two months later i set my parking brake again, and when i released it the light stayed on again(go figure) so i set it again and released it, but the light stayed on(then i did it like three more times and the light was still on) one time i had to get my rear left wheel plug because a nail was in it, i took it to a mechanic, he jacked it up and just started spinning the back wheel freely with no problem until he reached the spot that needed to be plugged. well i just noticed that i had heard a clicking sound underneath my car(found out what it was, no problem) and i had jacked the car up, and when i tried to spin the rear wheel it didnt, so im guessing the parking brake is still slightly engaged. and i have been driving for like three weeks with the brake light on(i like danger lol) but im guessing its the parking brake, any tips on how to depress it all the way, i looked at the cord and it seems like its released, but it also looks kinda chewed up and rusty

theory 2-brake fluid
i hadnt put any brake fluid in my car so i first got it until about 2 and a half months after, so im thinking hey the light is on because it needs brake fluid, so i check the master cylinder and its like half way full, so just to be safe i fill it up, get in the car turn it on and pump the brakes a couple times, but the light is still on.


theory 3 i need new brakes ?
im not really sure if i need new brakes, but one time the pedal went all the way to the floor(like a day after the brake light stayed on) and was acting a little funny, but besides that, i have been braking normally(although it does seem like the brakes are a little harder to push down now or have pressure built up in them) but i dont hear any screeching, which is normally a sign that you need new brakes.


help please because i dont want to be going 60 mph on the highway coming from work and my brakes give out on me when i need them most:lol2:


im guessing its theory 1 and the parking brake,

If your parking brake is not releasing due to rusty cables, they either need to be replaced or lubricated. If you have noticed any fraying of the cable inside the drum, of course, they will need to be replaced. As far as the brake pedal going to the floor; you need to inspect all brake lines & all four corners for leaks. If none found, the master cylinder is more than likely the culprit. In addition, if the pedal requires more pressure now to stop the vehicle than it did previously, I would suspect air in the system! It sounds like you need some professional on-site brake diagnostics. :uhoh:

If your parking brake is not releasing due to rusty cables, they either need to be replaced or lubricated. If you have noticed any fraying of the cable inside the drum, of course, they will need to be replaced. As far as the brake pedal going to the floor; you need to inspect all brake lines & all four corners for leaks. If none found, the master cylinder is more than likely the culprit. In addition, if the pedal requires more pressure now to stop the vehicle than it did previously, I would suspect air in the system! It sounds like you need some professional on-site brake diagnostics. :uhoh:


thanks fore the advice, ill probably have to get it looked at monday