Power Steering Pump Buying Guide

Hydraulic and electric power steering

Traditional hydraulic power steering (HPS) uses a vane pump driven by the engine's serpentine belt to pressurise power steering fluid. Pressure is routed through the steering rack via hoses, and a control valve in the rack reduces pressure assistance as the steering returns to centre, providing road feel. Hydraulic systems are robust and well-proven but consume engine power at all times, even straight-ahead driving.

Electro-hydraulic power steering (EHPS) replaces the belt-driven pump with an electric motor, reducing parasitic loss. Electric power steering (EPS) eliminates hydraulic fluid entirely, using an electric motor on the column or rack — these have no fluid-related failure modes.

Signs of a failing power steering pump

A groaning or whining noise that increases when the wheel is turned to full lock is the primary symptom of a failing hydraulic power steering pump. Low power steering fluid is the most common cause — check the reservoir level before assuming the pump has failed, as a slow leak from a hose or rack seal can reduce fluid to the point where the pump runs dry and cavitates.

Stiff or jerky steering at low speeds, fluid puddles under the front of the vehicle, and a burning smell from the engine bay (overheating fluid) are further indicators.

• Groaning on full lock
• Stiff or jerky steering at low speed
• Fluid leak under front of vehicle
• Check fluid level first before replacing pump
• Burnt smell from power steering fluid

Replacement and bleeding

Power steering pump replacement requires draining the system, fitting the new pump, refilling with the correct fluid type, and bleeding air from the system by turning the wheel lock-to-lock with the engine running. Always check the reservoir strainer for debris from the failed pump before filling — debris circulating through the system will damage the new pump and rack. Use the registration lookup to find the correct pump for your vehicle.

Frequently Asked Questions