The Hummer brake caliper has a big job to do-but who are we kidding? Everything on the Hummer has a big job to do. But once the engine has done its job and gotten that big chunk of iron moving, it's up to the Hummer brake caliper to stop it again before you go plowing through a red light or stop sign. To accomplish this seemingly monumental task, the Hummer brake caliper utilizes hydraulic fluid under extreme pressure-you know it as brake fluid. When you stomp on the brakes, brake fluid is routed to the Hummer brake caliper. The Hummer brake caliper then uses that high-pressure fluid to squeeze the brake rotor between the brake pads. The resulting friction is what stops your truck. You may remember from high school physics class that friction results in heat, and that's definitely the case in your Hummer brakes. The rotor and pads absorb and dissipate much of the heat, but the Hummer brake caliper still has to deal with tremendous temperatures. And, since the Hummer brake caliper has to deal with these temperatures at the same time it's clamping down on the rapidly spinning brake rotor, it goes without saying that the Hummer brake caliper is a strong, heavily built component. The Achilles' heel of the Hummer brake caliper is actually its hydraulic seals. After years of wear from the movement of the parts inside the Hummer brake caliper, the rubber seals eventually deteriorate and allow brake fluid to leak out of the Hummer brake caliper. When that happens the brake pads rapidly become contaminated, and replacement of the Hummer brake caliper and the brake pads is necessary. If you're handy, you can rebuild your own Hummer brake caliper using a repair kit. However, since you're dealing with your brakes, purchasing a Hummer brake caliper remanufactured by an expert, or a new Hummer brake caliper, is generally the best way to go. When you replace your Hummer brake caliper, add a set of high performance Hawk brake pads too-your truck will stop better than you ever thought possible!