Should You Replace Your Power Steering Fluid (And How Often?)

We’ve talked a bit about maintenance lately and more specifically, how often to replace certain fluids in your 4runner or Tacoma. Well, your power steering system can also use some attention from time to time.

Is replacing your power steering fluid actually necessary?

I’m sure there are A LOT of vehicles that make it through their entire life without ever having their power steering fluid replaced. Some would use this as an argument against it being necessary at all. But if you truly care about keeping your vehicle in the best condition possible, it might be worth doing.

Your power steering system contains a high pressure pump – and we’re talking really high pressure. It also has rubber seals throughout the system too. Over the years, the fluid can get dirty, break down, or even have moisture build up in it. 

There is plenty of reason to believe that worn out fluid can degrade the seals in your power steering system, in turn creating leaks (and potentially major repairs). 

So yes, your truck will probably still survive hundreds of thousands of miles without changing its power steering fluid. But doing so can certainly help to avoid leaks and repairs. It comes down to whether you’re willing to roll the dice or not.

Personally, I’m not much of a gambling man but I’ll admit that replacing my power steering fluid hasn’t been a top priority of mine. I’m happy to report that my 4runner currently has fresh fluid in it though – and that’s simply because I had to fill/bleed the system after replacing a rotten power steering hose:

How often to drain and fill your power steering fluid

Some people will tell you to do it every few years, others will say your power steering fluid should be replaced every 30,000 – 50,000 miles. In my opinion, it’s ok to decide based on a visual check.

The power steering reservoir is made out of clear plastic and it allows us to see the condition of the fluid inside. It’s very common for this reservoir to get so gunked up that you aren’t able to see the fluid through the black stains anymore. If the reservoir is getting badly stained, it’s safe to say your fluid is done.

You can also pull a bit of fluid out of the reservoir if you want to take a look at its color. It’s totally possible that the reservoir is stained from previous old fluid, but fresh stuff has since been filled up.

What fluid to run in your 4runner/Tacoma power steering

One thing is certain – do NOT run brake fluid in your power steering system. Oddly enough, there’s a good chance that you shouldn’t use power steering fluid in your 4runner or Tacoma either.

Most Toyota trucks actually call for Dexron 3 or an equivalent Automatic Transmission Fluid. The best way to know for sure is to check your owner’s manual – or it’ll often say right on the cap of your power steering reservoir.

Running the right fluid is important. Failing to do so can cause the rubber seals to not be lubricated properly or it can eat away at them. It’s better to be safe than sorry, so just run the proper stuff.

What’s the easiest way to flush your power steering fluid?

Replacing your power steering fluid doesn’t have to be complicated. There are essentially 2 different camps of people: those who simply suck the old fluid out of the reservoir and refill it and those who pull a line and bleed the old fluid out while pushing new stuff in.

Either option will do the trick. There’s no need to overthink this. The goal is to get rid of as much of the old fluid as possible. By using the first method, you won’t need any tools or to even get your hands dirty. The downside is that you’ll have to repeat the process 5 or 6 times before it’s safe to assume the system is now full of fresh fluid.

Pulling a line and bleeding fresh fluid through the system is probably a more effective method, but it’s not quite as easy. You’ll need to jack up the front of the vehicle and you might have to fight with some stubborn hose clamps.

Regardless of which method you choose to replace your power steering fluid, all that matters is that you do it if it’s dirty. It’s also important that you use the correct fluid. Running fancy synthetic fluids or additives isn’t necessary. Toyota is the one who engineered the system, so I’ll stick with what they recommend.