GM Service Manual Online
For 1990-2009 cars only

The power steering system is a closed loop system. The system consists of the following components:

    • The power steering fluid reservoir
    • The power steering pump
    • The power steering gear
    • The power steering pipes and hoses

The power steering fluid flows from the fluid reservoir through a hose to the power steering pump. The engine drive belt rotates the pump pulley. The pulley turns the pump drive shaft. The shaft turns the pump rotor. The vanes in the rotor pressurize the power steering fluid. The engine speed sensing type flow control valve controls the fluid pressure. This valve reduces the fluid pressure as the engine speed increases. The fluid flows, under pressure, from the pump, through the pipe and the hose, to the steering gear.

Important: DO NOT disassemble the power steering gear.

The steering gear is a rack and pinion type steering system. The steering gear has a control valve which directs the fluid to either side of the rack piston. The piston uses hydraulic pressure to move the rack to the left and to the right. The rack moves the tie rods. The tie rods move the steering knuckles. The steering knuckles rotate on ball joints and strut bearings and turn the front wheels and tires.

The power steering fluid flows from the steering gear, through the pipe and the hose, to the reservoir.

If the hydraulic assist fails, the driver maintains manual steering control. Under this condition, however, the driver must use more steering effort.