1997 Cadillac EL Dorado

Hi cadillac22, Welcome to the forum. First of all you must verify a brake is dragging. Try to push the car by hand, or park on a small incline, release the brakes, and see if the car coasts downhill on its own when in neutral. If it doesn't, if one wheel is really hot, that will tell you which one is dragging. Before it has a chance to release, jack that wheel off the ground. If you can't spin that wheel by hand, open the bleeder screw on the caliper. If that lets the brake release brake fluid is trapped and can't get back to the master cylinder reservoir. You can also crack the steel line open for just a second at the master cylinder. If the fluid is trapped there too, suspect the fluid is contaminated with petroleum product. That will cause the lip seals in the master cylinder to swell and grow past the return ports. The trapped fluid will keep the brakes applied.

If trapped fluid doesn't seem to be the problem, you may just have a sticking front caliper. That's not uncommon but GM doesn't have much trouble in that respect.

Caradiodoc

Ooooh. Once the light comes on there should be at least one diagnostic fault code stored in the ABS computer. It's important to not disconnect the battery or let it run dead until those codes have been read and recorded or that valuable information will be lost.

Don't worry about the Traction Control light. That one will turn on because the system makes use of the ABS system. When the ABS computer detects a problem, it turns the light on and disables the system. You already figured out that the ignition switch must be cycled off and back on to reset the system.

The good news is the light does turn off at times. That would tend to point to an electrical wire / corroded connector pin / sensor problem vs. Something in the hydraulic controller. If the light turns on right after shifting out of "park", the computer detected a problem during its self test that it does for a few seconds. If the light turns on randomly after driving a few hundred feet to a mile or so, check for cracked toothed tone rings by each wheel. The crack is detected as an extra pulse per tire revolution, but the computer will see the other three tires going the same speed so it knows you're not going around a sweeping curve, plus, it knows you wouldn't be doing that for up to a mile. GM has also been having a huge problem with front wheel bearings on front-wheel-drive cars. The bearings are not defective but they develop enough play to cause the built-in sensors' signals to drop out. This usually happens within 20,000 miles but I'm pretty sure it applies to newer model cars.

Caradiodoc

Can't speak specifically on a recall, but I do know it is common on GM trucks for the driver transistor to short causing the pump to continue running until the motor overheats. Repair involves a new computer and a new pump unless you catch it right away.
Unplugging the motor will prevent it from self-destructing.

What you could try the next time the brakes appear to be dragging is to unplug the pump motor, or just remove the fuse for the ABS system, pump the brake pedal until you lose the power assist, then see if the brakes still drag. Depending on which system you have, it is common to provide the power assist from pressurized brake fluid from the ABS pump. If internal leakage is taking place inside the hydraulic controller causing a brake to apply while driving, disabling the system will eliminate that pressurized fluid. Be aware though you won't have power assist so you'll have to push really hard on the brake pedal. If you have the Bendix-9 ABS system, you could have to pump the brake pedal up to 40 times to exhaust all of the pressurized fluid.

Caradiodoc

That only leaves the calipers. If you have rear disc brakes that have the parking brake built in, check for a sticking cable. Watch the levers move when a helper applies and releases the parking brake. There is less of a problem if you have the Chrysler style parking brake. That is much simpler design with a drum brake inside the rotor. Drum brakes don't usually cause dragging brakes. GM doesn't have much trouble with calipers on the front but they still shouldn't be overlooked.

Caradiodoc