The steering in my normally aspirated '98 S70 (302,000 km/190,000 mi) has gotten intermittently stiff, usually at lower RPM. The power steering fluid has turned a charcoal grey color, but the level does not look low. Last year I put in a rebuilt steering rack as the original was leaking, at which time the fluid was replaced with ATF. The serpentine belt was also changed last year and looks OK. Any ideas what could be going on?

Flush the PS fluid immediately! The grey color may be metal particles, rub some on your finger tips, indicating the pump may have problems.

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)

Hi Klaus,
Thanks for the quick response. Flushed the fluid. I couldn't feel any solid particles in it, but they may be too small. Would it be wise to install a filter in the return line (like a fuel filter)? How can I check the pump - open it up?

A dying pump will be very noisy at full lock/turn, that is when it works the hardest. I don't know if it can be disassembled.
If the fluid didn't feel gritty between your fingers, then there probably wasn't any metal. Magnafine makes filters, the same is used for the tranny fluid, but you will have to cut a line to insert it properly. A filter is about $25, plus a couple of hose clamps (not the kind you buy at a hardware store, but automotive hose clamp).

Klaus
--
The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)