When I got my oil changed, the mechanic said the power steering fluid was very dirty and needed to be flushed. How do I know this is true? How can I check "cleanliness" the PSF myself?

 

Was this one of those 'Oil Change in 15 Minutes', places??? They make loads of extra bucks by wiping the dipstick on a clean paper towel & then say; "OMG!!! Look at this....!"

There's virtually no time or mileage interval on PS fluid. If you had a GM product that used the PS fluid for your PS system and as a brake booster (Hydra Boost), it was at about 60,000 miles if you wanted to keep the pump in it.

If there's dirt in the fluid, that's generally caused by not cleaning the reservoir cap prior to removal. Any other 'stuff' (including metallic bits), in there would be caused by normal wear within the system, especially if you like to crank full left or right lock and hold it there while parking.

Any mechanical system can benefit from a lubricant change when it comes to longevity.... personally, I drain & fill my own PS system at 3 yrs/36,000 miles, (give or take), and I've never lost a pump or box yet.

It's up to you.

 

THanks, Jim,
No it wasn't an "oil change in 15" it was one of my regular full service mechanic shops.
Thank you for the information. Not being mechanical myself, I guess I'll pay the $75-$100 to have the work done.