Power Steering Pump

Power Steering Pump

Before the invention of power steering, a driver had to put a lot of force to the steering wheel to turn the front wheels, especially at low speeds. Fortunately, modern power steering systems do not require a driver to have good muscles, providing steering assist regardless of the vehicle’s speed. They rely on pressurized hydraulic fluid supplied by a high-performance pump. This pump is called a power steering pump.

A power steering pump is a heart of every hydraulic power steering system. Attached to the front of the engine and driven by a belt or gear, it pressurizes hydraulic fluid and sends it to the steering box via a high-pressure line. When the pressure exceeds a specific point, an internal pressure relief valve opens, redirecting the fluid back into the system. This prevents the power steering pump and the steering gear from getting damaged. 

Depending on your steering system, it can utilize a different type of steering gears. The most common types are rack-and-pinion assemblies and recirculating ball steering boxes. The first ones are usually found in lightweight cars, while the steering boxes are typical for larger cars and trucks. Regardless of your steering gear type, it sits between the steering column and the steering linkage, causing the latter to move your front wheels when you turn the steering wheel.

The power steering fluid constantly circulates throughout the steering system via high-pressure and low-pressure lines. The first one serves to transport highly pressurized fluid from the power steering pump to the steering gear, while the other one is used to return the fluid from the steering box or rack-and-pinion assembly to the fluid reservoir. The latter can either come as a standing-along part or be attached to the power steering pump.

While most new vehicles today come equipped with an electric power steering system that doesn’t have a power steering pump, there are still a lot of cars and trucks on our roads, which rely on a power steering pump to assist the driver. If the power steering pump fails in such a vehicle, the driver will experience several steering problems, including the following:

Hard steering, especially at low speeds

Your power steering pump is actually what helps you change the direction of your vehicle. If it starts malfunctioning, you’ll experience a lack of power steering assist when driving at low speeds or idling.

Abnormal noises from the steering pump

A whining or groaning noise coming from your power steering pump is a sign of a failing pump. The noise should become louder at higher RPMs or when the vehicle is moving around a turn.

Steering fluid leaks

The hydraulic fluid used in power steering systems is usually red or reddish-brown. That’s why if you notice a puddle of this color under the engine bay, you could have a leaking steering pump or line. If so, the entire power steering system should be checked for leaks.

Power steering pump troubleshooting and replacement

A power steering system is very complex. Problems with this system can be caused by its different components, which is why the entire system must be checked before replacing any of them. Unless you’re a mechanic, this job should be left to a professional.

The first step in your inspection list should be checking the hydraulic fluid level in the system. If it is low, it must be topped up. This will allow you to test the power steering pump and the entire system for leaks. If your steering pump is a source of abnormal noises, it should be checked with a stethoscope.

A faulty steering pump is usually not repairable. It must be replaced with a brand-new unit recommended by the manufacturer or of the same quality aftermarket part. Before replacement, the steering system should be flushed to prevent collecting dirt and contaminants in the system and damaging the new pump.