What is making my Lexus brakes pulse?
When you are experiencing a jerking or pulsing from the brakes, it is quite likely that it is being caused by a defect in the brake drum or rotor, rather than being caused by the anti-lock braking system. An out-of-round drum, or a warped rotor can cause unmistakable pulsating that is felt in the brake pedal.
Failure of the pad to properly retract is not at all uncommon. For the older drum systems, strong springs pull the brake shoes back from the drum. In the newer disc brake systems, resilient rubber seals are what pulls the pads back from the disc (or rotor). If these seals become contaminated or damaged by brake fluid, they are unable to do their job. This causes the pad to ride up against the rotor, prematurely wearing out.
When rotors are warped, this can cause the pads to prematurely wear out even if the rubber seal doesn't fail. Warped rotors wobble as they rotate, scraping against the pad as it turns. Over time the pad will wear out, causing the metal backing plate to damage the metal rotor.