Dan Ferrell writes about DIY car maintenance and repair. He has certifications in Automation and Control Technology and Technical Writing.
Power steering leaks are common. They are caused by pressure, wear, and vibration, and usually show up after the system has been in service for a good number of miles. But these leaks may not always be easy to find.
Leaks may appear because of:
- damaged hoses
- worn seals
- damaged fittings
- cracks in the reservoir
- worn pump bearings and seals
- worn seals in the rack and pinion
A power steering system operates under high pressure exceeding 1000 psi (6895 kPa). This pressure is enough to push oil through a worn seal or fitting or a damaged hose.
The following sections will help you locate a leaking component in your power steering system.
When working on your car, it's a good idea to have the vehicle repair manual for your particular make and model. The configuration of the power steering system changes from one model to the next, so even an experienced repair person might have trouble locating or replacing a component without the help of the manual for the car.
If you don't have the repair manual for your car yet, you can buy a relatively inexpensive, aftermarket copy online through Amazon. Haynes manuals come with step-by-step procedures for many maintenance, parts replacement, and troubleshooting projects you can do at home using mostly common tools. So you can use it to maintain, replace parts and troubleshoot other systems in your car as well.
In This Article
- Is Your Power Steering System Leaking?
- Hoses, Lines, and Fittings Leaks
- Pinion Gear Assembly Leaks
- Bellows Leaks
- Reservoir and Steering Pump Leaks
- Dealing With Power Steering Leaks
1. Is Your Power Steering System Leaking?
If you are not sure whether your steering system is leaking, you need to make sure this is so. Often, all you need is to check system fluid level and, sometimes, clean system components to verify the leak.
Check steering fluid level:
- Start the engine and let it idle for about 3 minutes.
- Turn the steering wheel from lock to lock (without hitting the stops) several times. This will help warm the fluid to operating temperature so that you get a more accurate reading.
- Turn off the engine.
- Remove the cap from the reservoir and read the fluid level at the dipstick attached to the cap (look for the HOT and COLD marks). On other models, you may see markings on the side of the reservoir to help you check fluid level.
If necessary, top off the system with the fluid recommended by your car manufacturer. Consult your car owner's manual or vehicle repair manual.
- You may hear a whining noise while turning the steering wheel. This may be a sign of low fluid in the system.
- Another sign of low fluid, and a possible leak, is the need to apply extra effort to turn the steering wheel.
You may need to check fluid level a couple of times, with a few days in between, to make sure the leak is in the steering system.
Clean Power System Components:
If you have confirmed your power steering system is leaking, you may not know where the leak is located. Dirt and grease can make it hard to see where fluid is coming out of the system. Sometimes, all you need is to wipe some components clean; other times, you may need to use a degreaser and pressure-wash the system.
- Park your vehicle on a level surface.
- Set your transmission to Park (automatic) or Neutral (manual).
- Jack up the front of the vehicle with a floor jack and secure the vehicle with jack stands.
- Block the rear wheels and set the emergency brake.
- Wipe fluid-soaked parts clean as necessary: hoses, power-steering pump, reservoir, bellows, rack and pinion assembly.
- If necessary, start the engine and turn the steering wheel from lock to lock without hitting the stops. This will pressurize the system and force the leak to appear. You may need to ask an assistant to do this while you inspect steering system components. Keep in mind that a leak may take several hours to become apparent.
Inspect potential leaking points:
- check hoses and fittings for signs of swelling
- check lines and fittings for wet spots and damage
- check the reservoir for cracks and leaks
- check the steering pump for cracks and leaks
- look behind the steering pump pulley for a wet area
- look at the bellows, at the ends of the rack and pinion assembly, for wet spots
2. Hoses, Lines, and Fittings Leaks
Hoses, lines and fittings are a common source of power steering system leaks.
- Check the condition of a system hose or line for deterioration. If necessary, replace the hose or line.
- Inspect hose and line fittings and connecting points.
If hoses or lines seem OK, but a leak seems to be coming from a fitting:
- Try tightening the hose or line connection. Consult your vehicle repair manual for torque specifications, if necessary.
- You may need to replace a connection O-ring or seal.
- Consult your vehicle repair manual for procedures and torque specifications for your particular system when replacing hoses, lines or seals.
Tip: Replacing seals, O-rings in a hose or line, or the hose or line itself, is something a DIYer may consider doing at home. Go over the instructions outlined in your vehicle repair manual, and make sure you got all the tools needed for the job.
The following video gives you some visual clues about inspecting steering system hoses and how to check them for leaks.
Checking Steering System Hoses
3. Pinion Gear Assembly Leaks
Seals and O-rings are the main culprits of pinion gear leaks as well.
If you've found a leaking point around the coupling assembly, you may need to replace:
- input shaft seal and valve assembly kit
- torsion bar O-ring
Keep in mind that leaking pinion seal may show up as a leak around the bellows. This is hard to distinguish from other seals in the rack assembly.
Tip: Replacing the steering rack and pinion gear with a new unit is a much better option because of the labor costs of rebuilding an old unit just to fix a leaking pinion seal.
4. Bellows Leaks
Leaks that appear to come out of the bellows are inner and outer rack and pinion seals. These could be your leaking points:
- outer rack seal (outside diameter)
- outer rack seal (inner diameter)
- inner rack seal
- pinion seal
Tip: These sets of seals usually require a complete seal kit set, since it's difficult to tell which is the one you are dealing with. However, just like trying to repair a leaking pinion seal, it's often better to replace the rack and pinion assembly. If necessary, consult with a reputable shop.
5. Reservoir and Steering Pump Leaks
Closely check the reservoir and fitting to hoses for leaks and cracks. Then check the steering pump around the casing and the shaft that connects the pulley to the pump.
On some models, when you need to replace the reservoir, you can replace just that part. On other models, you have to replace the pump and reservoir as a unit.
If you are facing a problem with the steering pump, you may find a rebuild kit for your particular vehicle model. But you may need special tools and the know-how to do the job. Often, it is easier, and recommended, to replace the steering pump as a unit, since you don't know in what condition is the rest of the pump's internal components.
Another advantage of replacing the reservoir or steering pump is that you may be able to do the job yourself with the help of your repair manual.
6. Dealing With Power Steering Leaks
Power steering system leaks need immediate attention. Driving your vehicle with low fluid in the system will cause damage to other components and a much more expensive repair later.
Although some steering system problems are difficult to do at home without proper equipment and skills, most car owners can tackle common system issues like replacing a steering pump, reservoir, hose, line, seal or O-ring. Your vehicle repair manual will help you identify components, show you the proper steps for your particular system configuration, and give you the torque specifications to reassemble components.
Some important tips to remember when dealing with steering system leaks:
- Replace parts with quality OEM components.
- Always apply the torque specifications listed in your manual when installing components.
- Refill the system with the fluid recommended for your particular application. See your repair manual.
- Bleed the steering system after completing the repair.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2020 Dan Ferrell