The power steering pump helps the driver turn the steering wheel with minimum effort. It does this by pressurising the hydraulic fluid within the system which assists steering movements. The power steering pump obtains power from the rotating engine crankshaft pulley while some cars employ an electrical system to power the pump. Power steering systems have been employed on luxury cars since the 1970s, but they can be found on almost all cars today, including affordable hatchbacks. It is important to identify symptoms of a bad steering pump in order to ensure safe and hassle-free driving.
This article will deal with power steering pump basics, bad power steering pump symptoms and ways to fix it.
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What is a power steering pump?
A hydraulic power steering system is made up of a steering rack and a steering pump which work together to reduce the effort of turning the steering wheel. Power steering pumps are usually of centrifugal vane type that can pressurise steering fluid to assist steering movements. Drivers state that the steering feels light and easy with power steering. These systems can be found on all types of cars today; however, they were first developed for use on luxury cars and heavy goods vehicles, buses and trucks that could not be steered without assistance.
Power steering hydraulic fluid is a yellow-coloured liquid that flows through the steering system. The steering pump spins at high revolutions to pressurise the steering fluid. This rotational power is borrowed from the spinning crankshaft of the engine via a pulley and belt system. The pressurised hydraulic fluid flows into the steering rack and assists the driver in steering left or right due to pressure differences in the fluid.
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Signs of bad steering pump
As with all mechanical components, power steering pumps are subject to wear and tear and will eventually fail after certain hours of use. Having said that, power steering pumps often last the lifetime of a vehicle or at least 200,000 km before needing an overhaul or replacement.
Still, power steering pumps can fail prematurely, which is a safety risk. The driver may lose control of the vehicle or find it difficult to steer away from obstacles. It is important to identify and fix a bad power steering pump as soon as possible.
Here are some common signs of a bad power steering pump that every driver should be aware of. This applies to mechanical pumps, but some symptoms will overlap with electric power steering systems as well.
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Stiff steering
Drivers may notice that they have to put in more effort to turn the steering wheel. It is characterised by resistance while steering, unresponsiveness and excessive free play (the steering moves but the wheel doesn’t). Turning the steering wheel should turn the front wheels spontaneously. In the case of unresponsive steering, the driver may lose control of the vehicle.
Rule out problems with the rack and pinion system and suspension before replacing the power steering pump.
Grinding noises while turning
When the power steering pump is faulty, it will strain to work and cause a whining noise, usually due to a lack of power steering fluid or damaged components in the pump. When bearings wear out in the pump, they can cause whining noises whenever you attempt to turn the steering wheel. Odd sounds may intensify as the engine rpm rises due to the increased rotation speed of the power steering pump. Avoid driving a vehicle with strange noises from the steering system.
Low level of power steering hydraulic fluid
Check the level of power steering fluid on a regular basis and look out for unusually low levels. Inspect the area underneath a parked car to check for power steering fluid leaks. You could even observe the engine bay around the steering system pipes and hoses for signs of leaking fluid. The power steering pump will eventually wear out without sufficient hydraulic fluid because it provides lubrication to the pump, in addition to being pressurised.
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Metal shavings in the power steering fluid
If the power steering fluid is oxidised and has tiny metal bits floating around, it means that the steering pump is wearing out and needs replacement. These particles will find their way through the steering system and damage other parts, leading to steering failure. Oxidation of hydraulic fluid occurs due to excess air entering the system through holes in the steering system pipes.
Ways to avoid power steering problems
A well-maintained power steering system can provide years of trouble-free driving. Ensure that the belts and pulleys are not squeaking and are providing enough power from the engine. Replace frayed or damaged belts to avoid them snapping during use. Check the power steering fluid for the correct level and top it up if necessary. Keep an eye open for hydraulic fluid leaks or odd-coloured liquid. The power steering pump should run silently without any groaning noises. This ensures that the bearings and other components are working fine.
Engine rpm should remain stable at idle and when turning the steering wheel. Rough idling while steering points to faulty sensors or a failing power steering pump. Inspect the steering system pipes and hoses for signs of damage or deterioration.
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Conclusion
Power steering is now a ubiquitous feature on all kinds of modern cars and SUVs, primarily because of the low cost of manufacturing and installing such systems in cars. Power steering pump failures are rare because of the advanced technology and superior materials used to provide safe driving.
Hopefully, this article will help you identify common signs of a bad power steering pump and ways to prevent it from affecting the rest of the steering system.
Have a look at some more informative articles on the Carorbis blog. You may want to read about The different parts of a car explained and Basic Steps On How To Replace A Ball Joint.
Frequently Asked Questions
Q1. How to diagnose bad power steering pump?
Ans. A steering pump is subject to wear and tear if not properly maintained. You may realise the steering pump is bad when you have difficulty turning the steering wheel or it starts to get unresponsive to steering inputs. The steering wheel may get stiff or start to whine as you go around corners. Look for hydraulic steering fluid leaks underneath the car after being parked for a while. You should be able to diagnose a bad steering pump for reasons of safety and comfort. An unresponsive steering could cause an accident if you cannot avoid an obstacle.
Q2. How do you know if power steering pump bearing is going bad?
Ans. The first sign of a failing power steering pump is difficulty in turning and steering the car. You will begin to hear squealing noises from the steering mechanism or when you raise the engine rpm. Start your vehicle and turn the steering wheel lock to lock. It should be smooth and turn without much effort, without making any groaning noises. Drive a small distance and try turning the wheel left and right. The wheels should respond to your input without delay or resistance. Avoid driving long distances if you identify any of these symptoms as it could lead to loss of control of the vehicle.
Q3. What are symptoms of a bad or failing power steering pump?
Ans. Some of the common symptoms of a bad or failing power steering pump include whining noises when you turn the wheel. A low level of steering hydraulic fluid will cause the steering pump to squeal as it tries to pressurise the system. The steering wheel may lock up while driving, adding a great deal of resistance when you attempt to turn the steering wheel. A stiff steering wheel is a sure sign of a failing power steering pump. The steering pump is driven by a belt and pulley which may begin to whine or drone when activated. Pay attention to unusual sounds from the steering system.
Q4. How to fix a bad power steering pump?
Ans. If you identify any of the symptoms of a bad steering pump, then you should consider replacing the component as soon as possible. It wouldn’t be worth fixing the steering pump as the hydraulic system may fail unexpectedly at a later date. Repairs to the steering pump may remove symptoms like stiff steering and grinding noises, but other components such as the rack and pinion may deteriorate over time. You may be tempted to just refill the steering hydraulic fluid and drive the vehicle for some time, but this could be a safety hazard as you never know when you may lose steering control.
Q5. Can bad power steering pump cause shaking?
Ans. The power steering mechanism is powered by a belt and pump which gets power from the spinning crankshaft. If the steering wheel vibrates or shakes while driving, it could mean a worn-out belt or missing teeth on steering system gears which cause uneven movements in the system. As the steering pump fails, it produces less pressure for the hydraulic system causing shudders and vibrations which interfere with smooth driving. Vibrations can also be caused by a low level of power steering fluid which puts added pressure on the steering pump.
Q6. Is the problem with a bad power steering pump or rack and pinion?
Ans. Problems with the power steering pump or rack/pinion system both cause stiff wheels, grinding noises and vibrations in the steering system. But the way to identify a problem with the power steering pump is to look for low levels of hydraulic fluid in the reservoir or leaks in the system (you should see a puddle of red fluid beneath the parked car). The rack/pinion steering system is lubricated with grease and uses no hydraulic fluid. A faulty rack and pinion system will result in excessive free play in the steering wheel (you turn the steering but the front wheels don’t respond).
Q7. Can a bad power steering pump cause rough idle?
Ans. The power steering pump takes power from the engine to work. If the power steering pump is failing, it will put more strain on the engine when the steering wheel is turned causing the rpms to drop momentarily. If your car is equipped with an onboard computer (ECU), the rpms will automatically rise to handle the extra load. This can cause erratic idling or a rough idle characterised by unsteady rpm. Special sensors in the hydraulic system measure the pressure and send signals to the ECU to adjust the engine speed. Replace the steering pump for a smoother drive.
Q8. How long will a bad power steering pump last?
Ans. Steering pumps do not require special attention during regular service unless they show symptoms of failing components. Just a top-up of power steering fluid should be enough to keep the system in good condition. Power steering pumps are known to last the lifetime of the vehicle without any issues. However, if your vehicle has run more than 200,000 km, it is advisable to inspect and replace the power steering pump before it fails and causes damage to other components. You should not drive a vehicle with a bad power steering pump as it may lead to loss of control of the vehicle or an accident on the road.
Q9. What causes a bad power steering pump pulley noise?
Ans. If the power steering hydraulic fluid has lost its lubricating properties and ability to pressurise the system, the pulley may be subject to excessive strain causing whining and grinding noises as the engine runs. Air bubbles in the power steering fluid reduce pressure and will cause faults in the power steering pump. A loose pulley may start to vibrate with a rattling noise, causing the belt to wear out and eventually break. Always keep the power steering hydraulic fluid at the correct level and stop driving if you notice excessive noise or a burning smell from the power steering system.
