1997 Chrysler Concorde

Sounds like a sticking front caliper. It was common practice in the '70s and '80s to rebuild them as part of a brake job to prevent this condition, but today, rebuilt calipers are real inexpensive and they come with a warranty. Many even come "loaded" with new pads.

It's a good idea to replace both of them at the same time so they're matched and will provide even braking.

"Before, the gas pedal would almost "stick" to the ground and I would have to pull it back with my foot in order to turn off the brake lights."

Did you mean to say "brake pedal"?

That is cause for concern. If the brake pedal went down too far, and now the calipers are locking up, that suggests the possibility of brake fluid contaminated with petroleum product. Remove the cap on the master cylinder reservoir and look at the rubber seal under it. If it is blown up and mushy, the fluid has been contaminated with engine oil, power steering fluid, or transmission fluid. This is really serious. EVERYTHING with rubber parts must be replaced and the steel lines must be flushed and dried. Failure to replace any rubber part will cause it to transfer the contamination to the new parts.

What was done to solve the problem of the pedal "sticking" to the floor? If a new master cylinder was installed, there is a very small chance the push rod is misadjusted and holding the brakes partially applied. This would happen all the time though and get worse the longer you drive. It could be relatively hard to notice if you only drive in town and for short distances. As the sticking brakes heat up, the brake fluid heats up and expands. Since the master cylinder is partially applied, the fluid is trapped and can't release back into the reservoir. The building pressure applies the brakes harder, so they get hotter and the cycle continues to get worse the longer you drive.

Fluid contamination can act the same way because the seals in the master cylinder will grow in size and push past the ports preventing the trapped fluid from releasing into the reservoir. A quick trick to identify if trapped fluid is the cause of the problem is to open the bleeder screw on each caliper. If a little spurt of fluid comes out, it was under pressure. The fluid will likely dribble out but there should be no pressure behind it.

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