Brake system and "Brake" light.
Okay, so researching this problem has taught me a lot, but I wanted to ask you guys for your experiences.
I bought this 94 V6 Automatic Camaro as a project. It was only $650, but it had a lot of small problems to fix. The brakes were bad, so I knew I'd have some work to do. One of the lights on the dash that was illuminated was the "Brake" light. I had assumed this had nothing to do with the brake problem as I thought this only had anything to do with the parking brake.
The pedal went all the way to the floor, but it didn't seem to be leaking fluid. I figured the system just needed to be bled. I jacked it up and started with the right rear wheel. I found out then that the rear brakes weren't engaging at all. After some research, everything I'd read suggested it was the master cylinder. I bought a new one, bench bled it, and installed it. Pedal was still soft, but I wasn't getting much air out of the bleeder screws. I figured I needed to drive it around the block, hitting the brakes hard and often to work the air to the ends of the lines. The good news was that I did now have rear brakes. The bad news is that the left rear cylinder was leaking. The drum was full of brake fluid.
Next time I'm working on it, I replace both rear wheel cylinders and once again bleed the system. I primed the cylinders before installing them. I got some air out when bleeding, but nothing significant. Pedal still soft. Tried driving the car again to work the air back, still not getting any air. Pedal still soft. Gave up and worked on other things for a while.
I decide to go back to the brakes. Since it still acted like it had air in the lines and the fluid was dirty anyway, I decided to flush the entire system. I made sure the reservoir was full, attached the "one man brake bleeder" tool to the bleeder screw and loosened it. I figured out it takes 25 full pedal strokes to fill that little bottle. Each time, I would empty it and top off the reservoir. Then repeat. I did this for each wheel until I saw clean fluid. For the right rear wheel, I got about 50 pedal pumps of nothing but air between the dirty and clean fluid. No air in the others, but at least now it has clean fluid. Pedal firmed up. Brakes work great. I think I'm done at this point.
Fast forward to the other day when I decide to remove the console so I can fix the "Brake" light issue. Come to find out, it's a single wire going to the switch at the bottom of the parking brake lever. When it's down, the switch is open. When you raise it, the switch closes and grounds that wire, causing the light to go on. Theoretically, you could just unplug that and make the light go off. But my light was still on. Did some google searches and apparently, there are two other sensors that can cause that light. One is the fluid level sensor in the reservoir. The other is a sensor in the ABS module/proportion valve. I decide to check those, and turns out, this car has neither that I can tell. At least not like the one in the console. There is NOTHING in the reservoir. I know because I just replaced it. The old one didn't have it either. There are wires going into the ABS module/proportion valve, but none that are a single wire like the brake lever. Also, none of them look like a sensor. They all just look like harnesses that work the ABS system. Plus, the abs system checks out. No ABS INOP light. So anyway, one of the things that can make that light illuminate is disproportionate pressure between the front and rear brakes ( according to the google searches ). That was a huge problem when I bought the car, but I fixed it all and the rear brakes work now, but the light is still on.
It looks like there are only 2 possible things going on.
1: There is air in the ABS module. My Haynes manual says to bleed it with the rear and front bleeder screws. The problem is that I don't see any bleeder screws. One link through google said to bleed it at the lines. Basically loosen the lines on top, one at a time, as you would a bleeder screw. But I don't think the Haynes manual would call the lines bleeder screws. Does anybody have a picture of the location of the bleeder screws?
2: If the light was on for too long, the sensor can be stuck. People have reported that even after fixing their problem, the light stayed on. Usually after going too long without fixing the issue. The solution is to go out now that it's fixed and just abuse the brakes. Build up speed, and just slam the brakes hard. Something about the pressure over the sensor will unstick it.
Can anyone here confirm either of those two issues? Does that brake light activate because of low fluid or air in the ABS unit?