On a car with anti-lock brakes, the wheel speed sensor (WSS) determines the speed of the wheels. To do this, the WSS sends an electrical signal to the rotors, which attach to the axle. When the GMC Sierra WSS works correctly, the anti-lock brakes receive the necessary information to stop on a dime.
Lift the truck with a jack. Make sure the jack stabilizes the vehicle securely.
Access the brake rotor by taking off the tire and wheel. Once you have access, remove it.
Detach the GMC Sierra WSS electrical connector. To do this, you need to remove the WSS cable mounting clips located on the knuckle, on the upper control arm and on the frame attachment point.
Remove the mounting bolt that holds the WSS in place. You can use a wrench or a ratchet and socket set.
Grab the WSS with your fingers and pull it out of the hub. Don't use any tools to pry the part, or you may break the WSS off in the hub or damage the sensor body.
Prevent debris from falling into the hub by plugging the WSS bore. Then clean the area.
Apply lubricant, a wheel bearing lubricant works well, to the O-ring and the hub and insert the new GMS Sierra WSS. Reassemble the components.
