It is the precision of the Toyota rack and pinion unit that is enjoyed when driving a vehicle on the road equipped with this type of steering. This precision is the direct reaction of the wheels to the input by the driver through the steering wheel. The rack and pinion unit is connected to the steering box in the lower front section of your Toyota. It is a hydraulically assisted set of gears that moves a steering bar which is connected to the front wheels. It is the hydraulic assistance that makes it possible for the great level of force to be applied without it coming from the driver. The metal components of the Toyota rack and pinion steering system do not generally wear out over time. The problem of these steering components is from the leaks that occur from the polymer seals on the shafts that extend out from the steering box. When one of these seals ruptures on the rack and pinion steering box, a puddle of thin clear hydraulic fluid can be found under the front forward driver's side of the vehicle. This will require this steering component to be rebuilt or replaced on your Toyota. If the leak in the power steering rack and pinion box is not rectified, then the hydraulic fluid will continue to leak causing the assistance from the power steering system to be negatively affected. The replacement of the rack and pinion is a long and complicated procedure, and when the new steering component is put into place the hydraulic system will have to be bled of any air that is trapped in the system. It is this bleeding of the system that frustrates most Toyota owners but it is required to return the power steering system to a functional status.