How To Check Power Steering Fluid

Powering steering fluid is an integral part of many cars today. Knowing how to check the power steering fluid level is an effortless job to learn, but you might find it invaluable.

Power-assisted steering makes driving a car much more manageable. In essence, it multiplies the force you put through the steering wheel, meaning it takes less effort to turn. The result? Much better car control.

Hydraulic power steering (there are other types, too) runs on power steering fluid. As a result, low levels mean turning will be more difficult.

In this article, you’ll find how to check your power steering fluid level, what it does, and why it’s so important.

What Is Hydraulic Power Steering?

Hydraulic power steering uses power steering fluid to manually assist the steering rack. When you turn the wheel, the system drives the rack left or right (depending on your input).

This mechanically pushes the rack in the same direction you’re turning, hence the term “power-assisted steering”.

Check out the video to see more detail about how a power steering system works when it’s fitted to a car, including the high-pressure and low-pressure return lines, O-Rings, seals, and pistons.

Hydraulic power steering is driven by a power steering pump. This, in turn, is powered by the engine’s crankshaft. It’s connected via a rubber belt known as the serpentine or drive belt.

The power steering pump forces the power steering fluid through the system, maintaining pressure. This allows the entire system to work.

How To Check Your Power Steering Fluid

Follow these simple steps to check your power steering fluid level.

1. Open the hood and locate the power steering fluid reservoir. It’ll most likely have a picture of a steering wheel on the cap or simply say “Power Steering”.
2. Look at the power steering fluid level through the side of the clear plastic container. If the reservoir is opaque, you’ll find a dipstick inside.
   1. You’ll see two markings – “COLD” and “HOT”. If you’ve just switched your engine off, use the “HOT” marking. If more than an hour has passed since you last drove, measure against the “COLD” reading.
3. Is the power steering fluid at the appropriate marked level? If so, close the hood and carry on with your day. If not, simply top it up.

Yes, it’s as simple as that.

Ensure you use the correct type of power steering fluid. Your owner’s manual will tell you exactly which to use. Two of the most common are synthetic and ATF-compatible.

ATF Power Steering Fluid

Some power steering fluids are also used in automatic transmissions: Automatic Transmission Fluid, or ATF. These tend to be found in older cars with non-synthetic, mineral-type power steering fluids.

If the product you purchase can be used as either ATF or power steering fluid, it’ll specifically say on the bottle. Dexron is a well-known example from GM. You shouldn’t use any old ATF in your power steering system.

Before using an ATF power steering fluid, ensure your car is compatible with the type. Check your owner’s manual for more details.

Synthetic Power Steering Fluid

Many vehicles today use synthetic power steering fluid. It’s created in a lab and is utterly unrelated to mineral oil. It’s (broadly speaking) the best you can get, providing optimal assistance and parts protection.

Synthetic power steering fluid may even be explicitly created with an individual car in mind. There are many different types developed to work in a variety of ways.

As always, check your owner’s manual for the type of synthetic power steering fluid you should be adding to your car.

Do You Check Power Steering Fluid With The Engine On Or Off?

You’ll find some people out there telling you to check the power steering fluid with the engine running. There’s no need for this. In general, opening any caps on your car before turning it on is asking for trouble.

Keep the cap on and switch the engine off before reading the power steering fluid level. You should then use the “HOT” level.

Just to confirm, the “HOT” level doesn’t mean the engine must be running at that moment. It refers to the level while the engine is warm from running.

Some cars don’t have a “HOT” level, so you’ll need to check it when the engine’s cold.

How Long Should Power Steering Fluid Last?

Power steering fluid should last a relatively long time. There shouldn’t be any leaks in the system (and if there are, they need to be repaired as soon as possible), so the only thing to watch out for is the fluid breaking down over time.

Assuming there are no leaks – if there are, the first thing the mechanic will check is the O-Rings – you should expect power steering fluid to last at least 50,000 miles or five years. Nowadays, it’s generally accepted that you should change it at about this period. Otherwise, the additives (such as corrosion inhibitors) start to break down.

Contaminated power steering fluid looks dark and dirty. If you notice this, you should change it immediately – no matter how long it’s been since the last replacement or top-up. It could be affecting the steering rack more than you realize.

Power steering fluid can wear down quickly if you do more city driving; that is, more sharp turns, putting more stress on the steering rack and power assist system.

Can You Drive Without Power Steering Fluid?

You can drive without power steering fluid, but it’ll make driving substantially more complex and could damage the steering rack.

The power steering fluid lubricates and protects the metal and rubber components in the rack, as well as providing the hydraulic assistance. Without it, you won’t be getting all that protection, and it’ll lead to premature failure.

In the immediate moment, steering without power steering fluid won’t make much difference, aside from feeling challenging to drive. However, in the long run, it’ll damage your vehicle.

This shouldn’t be a problem if you’re simply driving to the store to pick some power steering fluid up.

Some might tell you to use brake fluid instead of power steering fluid. Don’t!

Do All Cars Have Power Steering Fluid?

Power steering systems quickly caught on in the US. They were first fitted to the 1951 Chrysler Imperial, and within a few years, millions of cars in the country had them.

The rest of the world was much slower to catch up. Power steering didn’t become widespread in Japan until the late 1980s, with the UK and Europe waiting until the mid-1990s.

To some extent, it makes sense. American vehicles have always been enormous, powerful, and weighty, so power-assisted steering was vital. The smaller cars of the rest of the world had less demand for power-assisted steering – but everyone’s glad to have it now!

Finally, these days (since the early-2010s), electric power steering is becoming increasingly popular in passenger cars. An electrical system is technically simpler and means the driver can turn with minimal effort. However, it doesn’t provide much feedback, making precision driving nigh-on impossible.

In summary, if you have a very old American classic, a pre-1990 import, or a more modern vehicle, you might not have a hydraulic power steering system. As a result, your car won’t need any power steering fluid whatsoever.

Keeping Up With Power Steering Fluid

Depending on how much you drive, make it a general rule to check your fluids every couple of weeks or every month. This TLC will only take a couple of minutes of your day and could mean you catch a problem much earlier than you would otherwise, potentially saving you thousands.

With the car parked on level ground (and the engine off!), check the fluid levels of the:

• Oil
• Washer fluid
• Coolant
• Power steering fluid (if applicable)
• Brake fluid
• Transmission fluid (if possible)

Checking the power steering fluid regularly means you’ll notice if your car develops a leak or the fluid becomes contaminated. You can then get it fixed quickly, saving you money in the long run. 

Keeping the fluid topped up also means your vehicle will be easier to drive and feel healthier, so why not?