Power Steering Pump Failure Modes And Upgrade Options

Power steering, now a ubiquitous feature in modern vehicles, transforms the laborious task of steering into a smooth, almost effortless experience. At the heart of this system lies the power steering pump, a seemingly simple component with a crucial responsibility. But like any mechanical device, it's susceptible to failure. Understanding these failure modes and exploring potential upgrade options can extend the life of your power steering system and even improve vehicle performance.
Understanding the Power Steering Pump
Before diving into the problems, let's clarify the basic operation. The power steering pump is a positive-displacement pump, typically driven by the engine's crankshaft via a belt. Its primary function is to provide a constant flow of pressurized hydraulic fluid to the power steering gear or rack. This fluid pressure assists the driver in turning the steering wheel, reducing the physical effort required.
There are primarily two types of power steering pumps:
- Vane Pumps: These use rotating vanes that slide in and out of slots on a rotor. As the rotor spins, the vanes create chambers of varying sizes, drawing fluid in, compressing it, and then expelling it. Vane pumps are known for their relatively high efficiency and ability to maintain consistent pressure.
- Gerotor Pumps: These utilize an inner and outer rotor, with the inner rotor having one less lobe than the outer. As the rotors rotate, the spaces between the lobes expand and contract, creating suction and pressure to move the fluid. Gerotor pumps are often found in smaller vehicles and are known for their compact size and quiet operation.
Common Power Steering Pump Failure Modes
Power steering pump failures can manifest in several ways. Recognizing the symptoms early can prevent further damage and potentially save you money on repairs.
1. Noise
One of the most common indicators of a failing power steering pump is unusual noise, typically a whining or groaning sound that increases with engine RPM and steering input. This noise often points to one of several underlying issues:
Low Fluid Level: This is often the simplest and most easily rectified problem. Insufficient fluid allows air to be drawn into the pump, causing cavitation and the characteristic whining noise. Check the reservoir and top up with the correct type of power steering fluid.
Contaminated Fluid: Over time, power steering fluid can become contaminated with dirt, debris, and metal particles. These contaminants can damage the pump's internal components, leading to noise and reduced performance. This contamination acts like sandpaper, wearing down the precisely machined surfaces. A fluid flush and replacement are usually necessary.
Worn Pump Components: Internal wear, such as worn vanes, rotors, or bearings, can cause the pump to generate excessive noise. This wear reduces the pump's efficiency and ability to maintain pressure. This often requires pump replacement or a complete rebuild.
2. Loss of Power Assist
A more serious symptom is the loss of power steering assist, making the steering wheel significantly harder to turn. This often indicates a more significant pump failure.
Complete Pump Failure: In this scenario, the pump is no longer able to generate sufficient pressure, rendering the power steering system ineffective. This can be caused by a seized pump, broken internal components, or a completely blocked pump intake.
Internal Leakage: Leaks within the pump itself can cause a significant drop in pressure, even if the pump is still technically functioning. This often results in inconsistent power assist, with the steering feeling heavy at times and normal at others.
Belt Slippage: Although not directly related to the pump's internal components, a loose or worn drive belt can cause the pump to not spin at the correct speed. This results in reduced pressure and a noticeable loss of power assist, especially at lower engine speeds. Squealing noises often accompany belt slippage.
3. Leaks
External leaks are another common sign of a failing power steering pump. These leaks can lead to low fluid levels and subsequent pump damage.
Seal Failure: The pump's seals, particularly the shaft seal, are prone to wear and tear. Over time, they can become brittle and crack, leading to fluid leaks.
Housing Cracks: In rare cases, the pump housing itself can crack due to stress or impact damage, resulting in leaks.
Hose Connections: Leaks can also originate from the hose connections to the pump. Loose fittings, damaged hoses, or corroded connections can all contribute to fluid loss.
4. Foaming Fluid
Foaming power steering fluid is another indication of a problem. This occurs when air is mixed with the fluid, often due to a leak in the low-pressure side of the system.
Air Entrapment: A small leak in the suction side of the pump allows air to be drawn into the system. The air mixes with the fluid, creating foam and reducing the fluid's ability to transfer pressure effectively. This results in a spongy or inconsistent steering feel. This can also be caused by incorrect fluid type.
Power Steering Pump Upgrade Options
While replacement with an OEM pump is often the easiest solution, several upgrade options can improve performance and reliability, especially in vehicles used for performance driving or off-roading.
1. High-Performance Pumps
For vehicles subjected to demanding conditions, such as racing or heavy towing, high-performance power steering pumps are available. These pumps are typically designed to deliver higher flow rates and pressures, providing improved steering response and reduced steering effort at high speeds. They often feature:
- Reinforced Housings: To withstand higher pressures and temperatures.
- Improved Internal Components: Including stronger rotors, vanes, and bearings for increased durability.
- Optimized Flow Designs: To deliver consistent pressure even under heavy load.
When considering a high-performance pump, ensure it's compatible with your vehicle's steering system and that the appropriate hoses and fittings are used.
2. Remote Reservoir Kits
Relocating the power steering fluid reservoir away from the engine compartment can help to reduce fluid temperatures, which can extend the life of the pump and fluid. Remote reservoir kits typically include:
- A Remote Reservoir: Made from aluminum or plastic.
- Hoses and Fittings: To connect the reservoir to the pump.
- Mounting Brackets: To secure the reservoir in a suitable location.
This upgrade is particularly beneficial in vehicles with limited engine bay space or those that experience high engine temperatures.
3. Electric Power Steering (EPS) Conversion
A more significant upgrade involves converting to an electric power steering system. EPS systems replace the hydraulic pump with an electric motor that provides steering assist. This has several advantages:
- Improved Fuel Efficiency: EPS systems only draw power when steering assist is needed, reducing the load on the engine and improving fuel economy.
- Elimination of Hydraulic Leaks: EPS systems eliminate the risk of hydraulic leaks and the need for power steering fluid.
- Adjustable Steering Assist: Some EPS systems allow the driver to adjust the level of steering assist.
- Simplified Engine Bay: Removing the pump and associated lines cleans up the engine bay.
However, EPS conversions can be complex and require significant modifications to the vehicle's wiring and steering system. It's crucial to select a compatible EPS system and have it installed by a qualified technician.
4. Fluid Coolers
Adding a power steering fluid cooler can significantly reduce fluid temperatures, particularly in vehicles used for towing, racing, or off-roading. Lower fluid temperatures extend the life of the pump and fluid, preventing premature wear and failure.
Fluid coolers are typically installed in the return line from the steering gear to the pump reservoir. They can be air-to-fluid or liquid-to-fluid coolers, depending on the application.
Conclusion
The power steering pump is a critical component of your vehicle's steering system. Understanding its operation, recognizing the signs of failure, and exploring available upgrade options can help you maintain a safe and enjoyable driving experience. Whether you opt for a simple fluid flush, a high-performance pump, or a complete EPS conversion, choosing the right approach can significantly improve the performance and longevity of your power steering system. Proper maintenance and early intervention are key to preventing costly repairs and ensuring optimal steering performance.