It is the Lexus disc brake calipers that apply the force necessary to stop your luxury sedan. This is the braking component that makes use of hydraulic pressure and turns it into mechanical motion. There are either two or four disc brake calipers on your Lexus vehicle. They are always on the front wheels, and those models equipped with four wheel disc brakes also have them on the rear. The reason the Lexus disc brake calipers wear out is due to the seals on the pistons inside them crack or get punctured. This is the polymer seal that holds the hydraulic fluid in place on the outer edge of the moving piston. When it ruptures, brake fluid can be seen on the pavement near the front or rear wheels. If this is noticed, the disc brake caliper has to be immediately replaced or total brake failure will be the inevitable result. When the seal in the disc brake caliper first ruptures, the driver of the Lexus will feel a softening of the brake pedal as it is depressed. It will have a greater travel length to achieve the same braking power as before. This is the result of the brake fluid leaking out of this otherwise closed system. As the rupture grows the ability to stop your Lexus will diminish until total brake failure occurs. The replacing of the disc brake caliper is not complicated, but has to be preformed correctly. Because of the leaking fluid softening up the brake pads, they should also be replaced at this time. The other side of the vehicle should also get new pads just so both of them are equal. The final step in this replacement process is to bleed the caliper of any trapped air. With this not being done, the braking potential of your car will be diminished.