I'm guessing this is going to cost some coin to fix: I've got an old '94 Honda Civic with a rear left brake that has started to lock itself after sitting for a few days. I've noticed my brake fluid levels are going down, so I am guessing I have a leak somewhere. I fear either a brake line has a leak, or my master cylinder for the brakes needs repair/replacement. When the rear brake locks, I make sure the brake fluid levels are up to snuff, and then I usually try pumping the brakes and accelerate/power through the braked/pinched condition until the car rolls normally again. This can't be good for the car. This also happened when it was raining, and my tire just skidded for a bit since it couldn't develop enough traction to break the locked/pinched condition, and had to wait until the streets dried up a bit before getting the car rolling again. If the car has this condition, and I try backing up from a cold start, I usually get this loud pinch thud sound which feels like I hit something as I roll backwards, but it's just the pinched brake. When it first happened, I thought I ran over something and killed it. It was spooky. Any guesses as to how much this is going to cost? At least it's a second car, as I bought a relatively new car in September, fearing my old car was going to develop repair issues, like this one, and didn't want a primary car that was developing such issues.