I am no expert by any means, however, i would say no immediate harm has been done, but the oil should be replaced buy a standard PS fluid asap

PS fluids have specific characteristics which the motor oils do not have

good luck

 

Never heard of this happening, but I would immediately change out that fluid for new fluid, otherwise may damage seals and screw with your steering and become dangerous.

See:

 

I would have a thorough flush done and get the proper fluid in their ASAP.

 

Oops....there, not their

 

I would be finding another lube shop. No way that should've happened.

 

If you haven’t started the engine, siphon the reservoir and refill with proper fluid.

Sixto
05 E320 wagon 191K miles

 

And this sort of thing is why I do all the maintenance on our cars. Too many "techs" out there do stupid stuff like this, since it's not their car.

Yeah, either siphon the reservoir if no engine start (which I kinda doubt since a tech did it--you had to get home somehow), or do a fluid flush.

 

Only as a point of interest! Schneider National one of the nation’s largest trucking companies; ONLY uses ENGINE OIL in their power steering units. They also only change oil filters at 20k and completely change oil and filters at 40k. Just FYI! Go figure and Detroit engine engineering approves of it.

 

Totally different units from the ones in our cars. You can put Diesel fuel, straight vegetable oil, kerosene, and gasoline in US Military Deuce-and-a-half trucks, too, but don't try it in your M112, M113, or OM648 equipped Mercedes-Benz W211 unless you want problems.

 

Those Schneider trucks also hold ten or more gallons of oil.

 

I would get that flushed out asap. Both are very different formula and non-compatible. Make the guy pay for the flush and refill, that is plain stupidity on his part.

 

Your seals and hoses should be fine since both fluids are petroleum based.

 

Transmission fluid and "hydraulic fluid" when its called for is about the same as SAE 20. Depending on how much of a fill he topped off the reservoir with (and didn't notice the red or yellow fluid already in there? Wow) you can take your time on draining and refilling with the proper stuff. Rest easy, bigger stuff to worry about.