Brake Repairs and Service
Addresses questions pertaining to brake repair, brake service, and other related issues in the automotive brake system.
Why does my car pulsate when applying the brakes?
Usually the cause is warped disc brake rotors. Heat and wear on the rotors causes them to no longer be straight and true around the entire disc. The high spots on the disc surface change the pressure on the brake pads as the disc rotates. This makes it feel like someone is pumping on your brake pedal, which is the cause of the pulsation you feel.
How are warped rotors repaired?
This condition can be corrected by having the warped rotors “turned” on a lathe. In the turning process, the rotor disc spins at a very high speed while the high spots are shaved away to make the surface flat once more. A side effect of this type of fix is that the disc is now thinner and more susceptible to the heat that causes warping. This means the rotors may warp again, only sooner.
Is there a repair that is better than having rotors turned?
The best fix is usually to replace the rotors and install new brake pads. Some shops will reuse the old pads if they are not too worn. This works sometimes, but frequently it can result in brake squeal or other brake noise.