Not only do we rely on power steering to make controlling our car easier, but when the power steering goes out, it can become outright dangerous to try to drive. Your car's power steering uses a hydraulic system that builds up pressure as you turn the wheel, turning the tires to one side or the other. When there's an issue with the system, you'll know immediately because the car will become extremely difficult to steer and control.
Let's break down some of the most common problems associated with power steering. Then, we'll examine how you can diagnose these problems and what you can do to get up and running again.
The Parts of a Power Steering System
Your power steering system can be fairly complex, but in essence, it needs four aspects to function without any issues. These four aspects are a good engine belt, a functioning pump, clear hoses, and the right amount of fluid.
The power steering system is driven by the car's engine via a belt, which runs from the crankshaft to the steering pump. Some cars have a single serpentine belt that snakes through the engine pulleys, while others have multiple belts. If any belt becomes glazed, frayed, or breaks, it will cause the system to malfunction.
Power Steering Pump
The power steering pump is a simple machine that is driven by the engine belt using a pulley. Inside, it has a set of vanes that retract and spin inside an oval-shaped chamber. These vanes pull hydraulic fluid from the return line and force it with high pressure into the outlet. Your car's speed dictates the amount of flow the pump provides, meaning that it moves more fluid than is needed as the car goes faster. A pressure-relief valve ensures the pressure doesn't get too high in these cases.
A device called a rotary valve senses the force on your steering wheel so that the system knows when to assist you. The torsion bar is key to how this valve works. It's a thin metal rod that twists with the application of torque. This bar is connected to the steering wheel on one end at the spool-valve assembly, and to the pinion or worm gear at the other. As such, the torque in the torsion bar equals the torque the driver uses to turn the wheels.
When the steering wheel isn't turning, both hydraulic lines have equal pressure. When the spool valve turns, ports on the appropriate line open up to provide higher pressure and turn the wheels.
It's essential to have clear hoses and lines that are structurally sound. If these passages develop cracks and leaks or become clogged, your system can malfunction.
If your fluid levels are low, the system can't run as efficiently as it should. Your power steering fluid is the lifeblood of the system and is needed to maintain pressure to turn the wheels.
Symptoms of a bad Power Steering Pump
A few symptoms of power steering problems are:
Puddles, drips, or stains on the driveway.
Squealing sounds when turning the wheel.
Difficult steering or erratic behavior; the vehicle is difficult to control.
Some of the most common power steering problems you may face involve issues with hoses, slippage on your coupling, a slipping drive belt, or a power steering fluid leak. Let's look at each in detail.
Diagnosing Power Steering Problems
There are several steps to take to diagnose power steering problems. Be methodical and careful as you inspect the components, and you can catch many issues before they become too severe. First, check your power steering fluid level. This is accomplished simply by unscrewing the cap on the pump and looking at the level inside. If it's not full, your first step is to pick up some power steering fluid and refill it. Low levels may or may not be a sign of a leak, but generally, your system is sealed so it shouldn't lose fluid.
Next, inspect the lines and hoses around the pump, checking for wear and tear, cracks, softness, bulges, and other signs of weakness, or even active leaks. After this, have someone turn on the engine and turn the wheel while you listen for noises from the pump. Any noises can be an indicator of a loose or worn belt that needs to be adjusted or changed.
Finally, jack up the car's front end and check your rack-and-pinion seals for leaks. Those who have older cars may have to check the recirculating ball unit instead. If none of these steps indicates a problem, you may need to have a mechanic put the car up on a lift to check further under the car or to check for issues in the steering column.
Problems With Hoses
The hoses in your car wear down as they get older. After a number of years of use, some of them can become cracked and dry. They can also come into contact with other parts while you drive the vehicle, which can wear holes in the side. These cracked hoses can be the source of a fluid leak, or in the worst-case scenario, compromised hoses can actually burst from the pressure. Additionally, if your hose has been over-crimped at either end, you might notice the hose peeling back, which can lead to breakage and leaks down the road.
The only way to diagnose this problem is to periodically inspect your hoses along with the other system components inside the engine compartment of your car. Check to see if there are cracks or wear or if the hose feels spongy on the side. If your hose bursts, you'll immediately notice the sudden loss of pressure as it instantly becomes hard to steer.
Power Steering Coupling
This is another wear-and-tear issue that can come up after you've driven your car for several years. The coupling on the hoses can start to creep off due to the vibration of the engine. Again, a quick look when you perform your visual inspection of the components will reveal this problem. Often, if it's not actually damaged, a coupling can simply be re-secured and tightened to fix the problem.
Slipping Drive Belt
Another problem commonly faced is the drive belt slipping in the pump. A telltale sign of a slipping drive belt is a loud squealing sound when you turn the steering wheel, especially when you make a sharp turn that requires you to turn the wheel all the way to one side.
Power Steering Fluid Leak
The most common power steering issue encountered is a fluid leak. There are a number of different signs to look for that will allow you to diagnose these issues. First, and most obvious, will be the appearance of fluid under the driver's side of the vehicle. You may also notice a grinding sound while turning. This sound is an indicator that your fluid is very low, and you must address the problem immediately. Otherwise, you may have to replace the power steering pump entirely.
Repairing Parts of Your Power Steering
Repairing a Power Steering Leak
If you determine that you have a power steering leak, you'll want to take a step-by-step approach to repairs. Typically, your issue will probably be a hose that needs to be replaced. Your first step is to make sure you've got a safe place to work. A garage with a level floor is ideal, but at the very least, you need a flat and dry surface. You'll need to jack up the car or put it up on ramps using jack stands to provide extra stability. Be sure to lock the wheels.
Finally, always make sure your engine is off and the car is cold. This is because power steering fluid is very flammable. You want to avoid fluid landing on a hot engine or exhaust manifold.
After you've done this, you can start working.
Checking the Power Steering Pump
Your power steering pump and fluid reservoir will generally be located near the end of the steering column at the bottom of the engine compartment. Inspect it for leaks, and place paper on the floor so you can see if any fluid is dripping, and from where. If the pump itself is leaking, you can sometimes put a ratchet on the nuts and tighten them to stop the leak. Also, check your hose clamps to be sure they haven't come loose, and tighten them if they have. This can be the easiest fix for a leaky pump.
Replacing Cracked and Worn Power Steering Hoses
If you find wear and tear on the hoses, they will need to be replaced, as well. First, place a container under the engine to catch drips from the hose as you remove it. Next, locate the power steering hoses. The upper hose should be larger, and both should run from the pump to the control valve. One hose will probably require a screwdriver to loosen the clamp, while the other will require a ratchet or flare nut wrench.
Start with the lower hose, loosening the clamp then pulling the hose away from the pump, allowing the fluid to drain into the container. Then, loosen the lower clamp and pull the hose away. Attach a new hose and re-tighten the clamps. Repeat the process with the upper hose. Always be sure to route the new hose exactly the same as the old one, and don't over-tighten the fitting connections.
If you need to replace one hose, always replace both. This will ensure that your system ages at the same rate evenly.
After the hoses are secure, fill the reservoir with fresh fluid and start the engine to circulate the fluid. Stop the engine and refill the reservoir again. Continue this until the reservoir stays full, but be careful not to overfill it. Then, start the car up and turn the wheel from left to right. Leave the cover off and watch for bubbles to escape. Wait until they slow down. This allows you to bleed air out of the lines.
Check the hoses and system for leaks to be sure everything is secure. Finally, close the reservoir and road test the car to verify the repair.
Replacing a Drive Belt
If your drive belt is worn or broken, you'll need to replace it. This can be a complex process that is unique to each vehicle. First, track down a belt routing diagram for your specific car. You can find these in repair manuals or online. Carefully review the schematic, and keep it by your side for reference the entire time.
Obey the same safety procedures as outlined under 'Repairing a Steering Leak' above. It's also a good idea to disconnect your car's battery. Next, examine the way your old belt threads through and around the pulleys. Practice matching this routing with your new belt before pulling off the old one.
You will now need to release tension from the old belt. Be very careful when doing this; if the belt snaps, it could cause serious injury. Locate the self-adjusting tensioner, which is along the back side of the belt. It should look like a smooth roller. Place a tensioner tool on the tensioner and be sure you have room to pull the tool out after releasing it. Remove the old belt and check the pulleys along the route for wear and tear to be sure none of the pulleys are loose, noisy, or overly tight.
Line up the new belt following the route of the old one. Make sure it enters all the pulley grooves and that it is not twisted. Then, tighten the tensioner. Start the car and test the steering to be sure everything seems to work correctly. Finally, road test it to be sure there are no problems.
Obtaining Parts or Help
No matter how good you are with auto repairs, there's always something that seems outside of your realm of expertise. If you feel like the task is too much for your skills, never be afraid to turn to a professional for help or advice. This can save you thousands of dollars on costly mistakes and can even prevent an injury.
If you are ready to tackle your power steering pump repair, we are here to help. We offer an extensive selection of auto parts organized by make, model, and year. Take some time to browse our parts selection and place your order. If you don't see what you need, feel free to get in touch with us for help finding the perfect part for your vehicle today.