Operation CHARM: Car repair manuals for everyone.

Fading Pedal

CAUSES
- Severe or prolonged braking. During repeated braking, the amount of pedal effort/travel required to slow the vehicle increases as the ability of the brakes to dissipate heat decreases.
- Heat build up in brake linings. As the linings heat up, their "coefficient of friction" is reduced (they become slicker). As the coefficient of friction is reduced, more hydraulic pressure is required to stop the vehicle. More hydraulic pressure results in more heat which then results in more pedal fade.
- Glazed brake linings (overheated). Brake linings which have been severely overheated (cracked, shiny, charcoal like appearance) have a greatly reduced stopping ability and are highly prone to "pedal fade".
- Worn brake components. As the brake linings, rotors, and drums begin to wear, their ability to absorb and release heat is reduced significantly. This makes worn brakes more prone to "pedal fade".

WHAT TO CHECK FOR
- Inspect all pads/linings and shoes for sufficient lining and signs of overheating. Overheated linings will appear glazed, cracked and have a charcoal like appearance. Replace if linings are worn too thin or show signs of overheating.
- Measure rotor thickness. Replace both rotors if measurements are less than the minimum specification.
- Measure the drum inside diameters. Replace both drums if the measurements exceed the maximum specification.

NOTE: Always replace both drums or both rotors on an axle. Replacing only one will result in a different braking ability from side to side. This will produce a steering "pull" when the brakes are applied.