Oil in the power-steering-fluid reservoir: how bad is it?

Dear Car Talk | Nov 01, 2002
Dear Tom and Ray:
RAY: Well, we have all kinds of good news for you, Tom. Good news No. 1 is that it's only a '91 Isuzu Trooper.
TOM: Good news No. 2 is that it could have been worse. He could have dumped the wrong fluid into the transmission.
RAY: Good news No. 3 is that there wasn't room for him to put much motor oil in there.
TOM: Power-steering fluid is a thinner oil, without many of the additives you find in motor oil. And my guess is that the worst thing that will happen is, eventually, the power-steering pump might get fried. I'd be concerned about the seals in the pump being eaten away by the motor oil.
RAY: The solution is to simply flush out the system. Assuming the pump is not leaking already, just take it to any repair shop and ask a mechanic to drain the power-steering fluid and replace it with new stuff. It can be done manually, or by a machine that sucks out the old stuff and pumps in new stuff.
TOM: And if you're embarrassed, you don't even have to tell the mechanic why you're doing it. Tell him you and your son do it every year as preventive maintenance. And tell him there's no significance whatsoever to the T-shirt you're wearing that says "I'm with Stupid."
RAY: Well, we have all kinds of good news for you, Tom. Good news No. 1 is that it's only a '91 Isuzu Trooper.
TOM: Good news No. 2 is that it could have been worse. He could have dumped the wrong fluid into the transmission.
RAY: Good news No. 3 is that there wasn't room for him to put much motor oil in there.
TOM: Power-steering fluid is a thinner oil, without many of the additives you find in motor oil. And my guess is that the worst thing that will happen is, eventually, the power-steering pump might get fried. I'd be concerned about the seals in the pump being eaten away by the motor oil.
RAY: The solution is to simply flush out the system. Assuming the pump is not leaking already, just take it to any repair shop and ask a mechanic to drain the power-steering fluid and replace it with new stuff. It can be done manually, or by a machine that sucks out the old stuff and pumps in new stuff.
TOM: And if you're embarrassed, you don't even have to tell the mechanic why you're doing it. Tell him you and your son do it every year as preventive maintenance. And tell him there's no significance whatsoever to the T-shirt you're wearing that says "I'm with Stupid."
Got a question about your car?