Rear brakes sticking lightly & Brake light comes on and off

[32valvesftw]

Originally Posted by staminqia

What kind of a repair did you do to the wiring harness? were your brakes sticking or just the light came on and off?
any help here would be appreciated.

I pulled the harness apart disconnected the wires cut them and installed new ends then stuck them back into the harness. How bad are your brakes sticking? Did the shop check and record pad thicknesses. Normally if a caliper is stuck the pads will wear prematurely and one will wear more than the others. Disconnect the harness and see if the light stays on. It was several years ago, so details are sketchy.
As others have mentioned any competent shop can assess your braking system. These are not very complicated braking systems.
If the wiring is OK I would think you have an issue with master cylinder leaking internally and causing a temporary imbalance in the system when you apply the brakes.

[staminqia]

Car only has 19k miles. Brake fluid is filled just to the neck of the reservoir. It's a 92. I will disconnect the sensor that seems easy to do to see if light turns on or off.. Where is it located? I wish there was a good video on how to adjust emergency brake at caliper, can't find a good one.

[Ccmano]

Some information for you on the C4 ABS breaking system and how it's controlled.
H

https://www.corvetteactioncenter.com...ction-control/

[TX '90 ZR1]

Go to the top of the technical postings page in this forum and select the sticky that is labeled "Solutions". Scroll down to section 5 and then to the section labeled "Brakes". Lots of info there.

[staminqia]

I think I am going to try and diagnose this problem after sitting on it over night and reading a ton of posts. I am thinking to do the following tasks
1. remove rear wheels and inspect wheel spin
2. somehow remove any pressure from E brake (need to figure out how to do this) if this concluded that the wheels spin freely then I know where the problem lies. If this is the issue than I have to adjust the E brake tension. Might have to remove the driver seat to get to the e brake mechanism.
3. if E brake is not the issue than I need to check calipers sticking. may have to rebuild the calipers and flush the system fluids.

If this doesnt work than it has to be something with ABS components.

Thoughts?

[32valvesftw]

You can disconnect the ebrake at each wheel by unhooking the cable.

[staminqia]

Originally Posted by 32valvesftw

You can disconnect the ebrake at each wheel by unhooking the cable.

Awesome, that could give me an idea if its an E brake issue. If its not, then I will go next to the calipers sticking.
Question how do I know if its a caliper that needs replaced or a bigger problem?
For an example with the E brake disconnected how do I know which caliper is causing the stick? - space between pads and rotor on each side? If I see one left Rear or right rear side pads touching rotors or not? what if both side pads are touching rotor, does that mean I have a bigger issue becuase its affecting each rear brake?

Lastly should I flush all of the brake fluid first before I do any of this diagnostic or after?

[32valvesftw]

Typically a caliper that is stuck will have a pad that is very worn compared to the others, if it has gone on for some time. Or the wheel will be noticeably harder to turn. I just went through this exercise on my daughters car. Three rear pads were almost new, one was down to the metal backing. Some amount of dragging is OK, I would not expect the wheel to spin freely like a bicycle wheel.

If I were in your shoes, I would flush the brake fluid first as that may clear up your issue, do not let the reservoir go dry, and plan on putting a liter or more of fluid through the system, you want clear fluid to come out of the bleeds.

Each rear wheel has an ebrake cable going to it. They can be disconnected individually.

[staminqia]

Originally Posted by 32valvesftw

Typically a caliper that is stuck will have a pad that is very worn compared to the others, if it has gone on for some time. Or the wheel will be noticeably harder to turn. I just went through this exercise on my daughters car. Three rear pads were almost new, one was down to the metal backing. Some amount of dragging is OK, I would not expect the wheel to spin freely like a bicycle wheel.

If I were in your shoes, I would flush the brake fluid first as that may clear up your issue, do not let the reservoir go dry, and plan on putting a liter or more of fluid through the system, you want clear fluid to come out of the bleeds.

Each rear wheel has an ebrake cable going to it. They can be disconnected individually.

Thank you, good advice. I agree I will flush first with new clean fluid.

[Ccmano]

What year is your car?
H