Power Steering Fluid

What is power steering fluid?

airdrie power steering
Fluid flow in a traditional power steering system.

Some vehicles – especially those built before 2010 – use a hydraulic power steering system that is filled with power steering fluid. This fluid has two jobs: it provides the hydraulic “push” that helps steer your wheels back and forth, and it lubricates all of the moving parts in the system. 

Your power steering fluid is pressurized by your power steering pump and fed to a steering rack or steering gear box, where the hydraulic force helps you turn the steering in one direction or another.

Does power steering fluid ever need to be changed?

Like other automotive fluids, power steering fluid eventually wears out, and needs to be replaced. It contains detergents, corrosion inhibitors, anti-foaming agents and other additives that eventually lose their effectiveness, causing excess wear inside the pump and steering gear. 

However, power steering fluid is often over-serviced by lube shops or businesses trying to make a quick buck. Because it’s normal for the fluid to darken over time, it’s important for car owners to keep track of when their power steering fluid was last changed, and replace the fluid based on mileage more than just condition. (Very contaminated fluid should still be replaced regardless of mileage, of course.) Most car manufacturers don’t specify a replacement interval for power steering fluid, but we suggest a fluid change every 100,000 km as an inexpensive way to prolong the life of your power steering components. 

Replacing a part? Change the fluid.

airdrie mechanical repairs
This magnetic filter can help prolong the life of new steering parts.

There’s one time when flushing your power steering fluid is very important: after replacing a failed steering part. A worn-out steering gear or pump will sometimes fill the system with fine metal filings and debris as it fails internally, and this needs to be cleaned out to prevent damage to the other parts in the system – and the new part you’re about to install! In fact, most parts manufacturers won’t provide a warranty on a new power steering pump or gear if your repair invoice doesn’t show that a proper fluid flush was performed at the same time.

Sometimes when a system has been really contaminated with metal debris, we will go so far as to install an inline magnetic filter in your power steering return line. Over time, this will trap any filings that we aren’t able to flush out during the repair – protecting your new parts going forward. 

Topping up power steering fluid:

airdrie power steering repairs
Power steering fluid expands at it heats up. If your vehicle has been sitting for a few hours or more, fill the fluid to the “cold” mark. 

If you notice that your power steering fluid is low, there are two things that you should do:

  1. Fill the fluid to the correct level, using the correct fluid as required by your vehicle manufacturer.
  2. Have a qualified professional inspect your power steering system for leaks.

It’s not normal for power steering fluid to ever need a top-up. Your power steering system is sealed, with the fluid circulating in a continuous loop from – and then back to – the fluid reservoir. Power steering fluid doesn’t burn off or evaporate over time, so the only way for the system to become low is if the fluid is leaking somewhere. 

Leaking power steering fluid:


Power steering fluid leaks should be inspected right away to determine how severe they are, and repaired as soon as possible. Sometimes, a simple repair like replacing a leaking hose can become a lot more expensive if it’s neglected too long, running the system low on fluid and damaging other parts like the pump. 

If you have a power steering fluid leak, we’d be happy to provide an honest answer on what’s wrong. This is usually a quick, inexpensive inspection; after which we can provide an estimate for any required repairs. 

Is power steering “stop leak” a good idea?


Because repairing some power steering leaks can be costly, customers may be tempted to try a stop leak product in their power steering system. While the idea of this “mechanic in a bottle” sounds good, the reality is that these products usually don’t work – and can cost you more money in the long run. 

These products contain seal-swelling agents that can sometimes stop leaks because they cause seals inside your steering pump or gear to expand. However, they don’t repair the underlying reason that the seals are leaking in the first place – like worn bearings, for instance – so the “repair” is usually temporary if it works at all. Over time, these chemicals continue to swell seals throughout the system; softening and weakening hoses, and sometimes causing internal failures of the steering gear.

Our advice is to keep your power steering fluid topped up until you can afford to perform a proper repair. If the repair includes a high quality replacement part, it should be the last time you ever have to replace it for the life of your vehicle. 

Replacing power steering fluid in Airdrie:

If you’re looking for a skilled team to provide top quality service or repair of your power steering system, My Garage is here to help! We only use approved OEM power steering fluid and genuine OEM parts for the best possible repair. We also back every repair with Airdrie’s best workmanship warranty. Even if you just have a question, feel free to drop us a line any time!