Seeing as many vehicles switched from hydraulic power steering to electric power steering by the mid-2000s, fewer and fewer cars have power-steering fluid anymore. (Only the hydraulic systems use power-steering fluid.) But if your car is one that still has hydraulic power steering, your owner’s manual is the best source for when, if ever, the power-steering fluid should be changed. (If you’re not sure whether your car has hydraulic or electric power steering, you should be able to find the answer by doing an internet search for, “Does the [year/make/model of your car] have hydraulic or electric power steering?”)
Related: What Fluids Should I Top Off?
One indication that the power-steering fluid level should at least be checked is if the steering wheel becomes harder to turn or you hear a whining noise coming from the power-steering pump.
However, note that power-steering fluid can degrade and pick up contaminants and debris over time that can cause damage to other parts of the steering system, and those parts can be very expensive to replace. Thus, it may be worthwhile to change the power-steering fluid whether the maintenance schedule calls for it or not. This might be particularly true if you do a lot of city driving, which wears the steering components more than highway driving. Common recommendations are roughly every four years or 50,000 miles, or if the fluid is dirty, looks foamy, smells burnt or contains particles.
How Do You Change Power-Steering Fluid?
While having the power-steering fluid flushed by a professional is probably the optimal way to do it, that involves quite a bit of labor and therefore expense. You can do a full flush yourself, but be warned that it’s a very messy job that can require removing a hose (and perhaps a rusty old clamp) and working in tight places, ideally with another person to help. Far easier — and cheaper — is to do a partial flush using a fluid extractor or common turkey baster (that will never again be used for food).
To perform either do-it-yourself method, the first step is to make sure you buy the factory-recommended type of power-steering fluid. It could be mineral-based fluid, synthetic fluid or automatic transmission fluid. On some cars, the type you need may be printed on the power-steering fluid reservoir’s cap — which you’ll have to find anyway. You should buy a good-sized bottle of the proper fluid, as you’re likely going to be wasting some.
To do a partial flush, remove the cap to the power-steering fluid reservoir. (It would be best to do an internet search to learn how to do a full flush if you wish to do it yourself.) Squeeze the bulb of the turkey baster and insert the tube down to the bottom of the reservoir. Release the bulb, suck up the fluid, and then squirt the fluid into an empty container. Repeat the process until the fluid is almost all out, and then fill the reservoir with new fluid to the proper line (either on the side of a see-through reservoir or on the dipstick attached to the cap). Be sure to not overfill the reservoir by checking the markings, as there will likely be one for “cold” and one for “hot” — hot meaning the car has just been driven quite a ways. Replace the cap, start the car, and drive it a short distance, turning the steering wheel all the way in both directions.
Then, repeat the whole process two or more times (remembering that the fluid may now be considered “hot”) until the fluid you suck out looks about as good as the new fluid. You have to repeat the process multiple times because there’s quite a bit of fluid that’s circulating through the system, so just emptying the reservoir isn’t getting it all.
When you consider the considerable cost of replacing some parts of the steering system that could be damaged by bad fluid, a few dollars for new fluid and a little bit of time to put it in really adheres to the old adage, “An ounce of prevention is worth a pound of cure.”
