Your brakes, one of the most important parts of your car, generally controls the motion of your vehicle. If you have braking system problems, you'd better hope not crash into the nearest tree, post, or person. Your Toyota Tundra brake pads are an essential component of your braking system; if you encounter a problem with them, you need to troubleshoot it and repair it as soon as possible.
Brake noise is caused by friction between the pads and drum or rotor when the brakes are applied. Occasional squeal is normal and not a functional problem and it does not indicate the loss of braking effectiveness. When the brake noise occurs all the time, check the lining condition; if it is glazed, the lining should be replaced or cleaned using emery cloth.
Squeal can be caused by a weak hold down spring or return spring as well as missing, damaged, or improperly-installed anti-squeal shims. Anti-squeal shims help dampen the vibration, which occurs when the brake pads make contact with the disc. Anti-rattle springs, on the other hand, are used to position and hold the pad as rigidly as possible to reduce pad movement in the caliper assembly. Overall, this reduces the noise caused by vibration, so make sure that both components are positioned properly.
When assembling brake pads to the caliper assembly, inspect the shims and fitting components for deformation, burrs, cracks, wear, or rust. Anti-squeal springs and support plates may be reused if they are in good condition.
Generally, the front pads will wear long before the rear pads since 75 percent of the braking effort is handled by the front. And generally, all of the four front pads (two on each side) are likely to show the same amount of wear. Inner pad wear usually occurs when the piston can't retract properly as it may be binding in a scored cylinder or the piston seal may be distorted. The brake pad may also be binding on a corroded caliper bracket.
Outer pads will wear prematurely if the caliper bracket or (more likely) the caliper pins are corroded or if lubricated with the wrong lubricant. They should also be cleaned with emery cloth and lubricated with brake lubricant.
The occurrence of both pads on one side getting thinner than pads on the opposite side is generally caused by a hydraulic problem, although it may also be caused by a sticky piston. It's also possible that there's a hydraulic restriction higher up the line than the brake hose on the side with the brake pad wear. For example, a faulty antilock braking system (ABS) modulator may not allow the release (return) of pressure on that side.