There are either two or four Chevrolet disc brake calipers on your car. They are mounted on the wheel carrier or steering knuckle located near the wheel hubs of your Chevrolet. This is the hydraulic device that applies pressure to the pads so friction is forced on the brake rotor and your car can have its forward momentum slowed or stopped. The part of the disc brake caliper that moves is the piston in the cylinder chamber. Because it moves, seals are necessary for the fluid to be held in place. These seals sometimes wear out and begin to crack. At that point, replacement or the rebuilding of the disc brake caliper is required. If one of the Chevrolet disc brake calipers is leaking, a wet spot of hydraulic fluid will be found on the break rotor and/or on the ground near the wheels. This oil is clearer and less dense than motor oil. As a driver you may also want to check the level of fluid in the reservoir on top of the master cylinder if the brake pedal feels spongy. The spongy feeling in the brake pedal is from air entering the hydraulic system. Air compresses at a different rate than the hydraulic fluid and will affect the feel on the pedal. It will also have a negative effect on the stopping ability of your Chevrolet car. There are both new and rebuilt disc brake calipers available today from most stores and shops that repair brakes. Once replacement is competed the brake lines should be bled to remove any air that might be trapped in the system. This will restore the feel your brake pedal had before the leak occurred. If the leaking disc brake caliper is ignored on your Chevrolet for too great a time, the driver's ability to stop their car will be impaired and total brake failure can occur.