Will Water Harm the Power-Steering System?

Dear Car Talk

Dear Car Talk | Jan 12, 2017

Dear Car Talk:

I added a little bit of water to my power-steering system on my 2008 Ford Ranger. Did I do any damage? I removed as much as I could, and it seems to work fine. But what about long-term? Will it harm the system? -- Craig

Ah, the old "top up windshield-washer fluid into the power-steering reservoir" trick. You're not the first, Craig. A small amount of water is unlikely to do much harm. Most of the fluids in your car end up absorbing a little bit of water over time. They have to be able to handle that, because moisture gets everywhere.

But that doesn't mean water is good for power steering -- it's not. Certainly not as good as power-steering fluid. So your best course of action would be to flush the system.

It's not hard to do. You can just pull off all the hoses and let the fluid run out into a basin. If you really want to flush it well, you can actually flush and replace the fluid while the car is running.

An easy way to do this is to remove the return hose, which goes from the power-steering rack back to the pump. Then, with a clamp, you can pinch off most of that hose to keep the fluid from gushing out of it at 100 mph. Then start the engine, and while a buddy keeps the pinched-off return hose pointed toward the drain bucket, you pour new power-steering fluid into the reservoir while the old stuff runs out. That keeps the pump from pumping dry, and replaces pretty much 100 percent of the fluid.

If you've got a friend who can help you, that's what I'd recommend. Just tell him not to wear his finest clothes when he comes over to help you -- especially if he's manning "the gusher." Good luck, Craig.

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