Q&A: Ride's surging back and forth when braking; no radio static when brake ... - TheChronicleHerald.ca
Up until about 10 months ago or so, the vehicle braked smoothly. I do not notice any pulsation in the brake pedal. I checked all the wheels by jacking up the frame and spinning the wheels by hand. One rear wheel had a spot where the brake pad rubbed against the rotor and then a portion of the rotation where it did not rub. Using a flat feeler gauge, I measured the gap between the pad and rotor where it was not rubbing. The lateral run-out of the rotor is way too high and this will cause brake pulsation. Because it is on a rear wheel, you won't feel it in the brake pedal as much. So what caused it. A brake rotor can be warped by applying the parking brake when the brakes are very hot. You should always let the brakes cool by driving a bit without heavy brake application before applying a parking brake. The rotor can also be warped by uneven torque on the wheel nuts. If the torque is corrected in a couple 100 kilometres, the rotor will usually be OK. If you have driven more than that, the rotor will likely need machining or replacement to correct the warp. Finally, if the wheel has been changed, dirt or rust can fall between the rotor and the axle or the rotor and. Source: thechronicleherald.ca
