Most modern cars contain power-assisted steering devices. These devices make turning the wheels of a vehicle easier. This power-assisted steering technique is accomplished by using a power steering pump, which is driven by the engine of a car through a belt-and-pulley device.
The power steering pump uses hydraulics to push fluid into the steering gear box. This fluid is used to assist in turning the wheels of a vehicle. When a driver turns the steering wheel, small ports open up in the steering shaft, which provides high-pressure fluid that assists the shaft in turning the wheels.
Chrysler Corporation was the first car company to commercially offer power steering in its vehicles. This was first introduced in the 1951 Chrysler Imperial as a luxury item. Most commercial vehicles prior to 1970 used manual steering units. These vehicles required large steering wheels to apply the additional leverage needed to turn vehicles without assistance.
A power steering pump requires special power steering fluid to perform correctly. This fluid is similar to engine transmission fluid and should be changed on a periodic basis. Most manufacturers suggest that power steering fluid be changed after 40,000 miles of usage.
Power steering is a mechanical device and at times may have defects or failures. Car owners should inspect all hoses, clamps, and fluids on a regular basis for abnormalities. If a power steering device has signs of leakage or failure, it should be quickly inspected by a qualified mechanic. Dirty power steering fluid may contaminate the power steering pump and cause permanent damage if not corrected quickly.
Cars with assisted power steering should be easily turned while the car is operating. The power steering pump only functions when the car is running. In the event of a failure in the power steering unit the vehicle will become difficult to turn because the assistance will be lost. Difficulty in steering may also occur if the power steering fluid level is lower than recommended.
The days of the power steering pump are limited as future designs are moving away from manual hydraulics. The new design in power steering is the electric power steering system. This new system replaces the pulley design and saves valuable energy. Electric power steering is available in most modern trucks today.
Electric power steering uses steering sensors to detect the position and rate of turn in the steering wheel. This information is feed to a steering computer module, which in turn moves the steering shaft appropriately. This new approach will require future computer chips and sensor replacement instead of the mechanical replacement of power steering pumps today.