Help! I put antifreeze in my power steering reservoir

I’d just changed my oil and was topping off my fluids, when I realized I’d just put antifreeze in my power steering reservoir. Doh!

Thankfully, I hadn’t started the car, and the way the reservoir is situated, both of the tubes connected to it go uphill. So I figured the antifreeze was isolated.

I went to the store and bought a quart of power steering fluid. Then I came home and disconnected the hoses to the power steering fluid reservoir and drained the reservoir and the two hoses leading to/from it.

Then I removed the reservoir and washed it thoroughly and let it dry overnight.

I reinstalled the reservoir and filled it with fresh power steering fluid. Then I ran the car a few moments and topped it. Now it appears to be working as normal.

My questions are these:

Is it likely that I got it all?

Are antifreeze and power steering fluid like oil and water, or do they assimilate?

While I went to the store, did the antifreeze permeate my power steering system like skim milk in decaf? Or did the antifreeze just sink to the bottom of the reservoir and come out when I drained it?

Thank you

As long as you didn’t start the engine, you got it all out.


I would guess that it floats, but why not try it and see. Put a little of each in a jar and shake it up to see what happens. Some of the chemicals in the coolant might partition into the PS fluid. I would try to do a fluid change just to be on the safe side.

Good idea. But how does one purge a power steering system? Is there a drain plug on the rack down underneath somewhere? A fitting to loosen?

There is no drain plug on the rack and pinion assembly. What are you so worried about? You never started the engine so all the coolant was in the reservior. You drained that, plus whatever came out of the disconnected hoses. So there’s no coolant left in the power steering system. If you had started the engine, then you would have pumped the coolant throughout the power steering system and then it would need to be flushed. But since that didn’t happen, you’re good to go.