When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Yes, the power steering reservoir contains a filter. How effective is it? Don't really know. If the filter was clogged, your steering would be consistently unassisted regardless of speed.
Something worth investigating. The SPS system provides full steering boost at a stop, and then gradually diminishes the assist as speed builds. It uses a solenoid (Y10 below) on the rack to modulate oil flow. Does your steering lighten up if you're moving slowly?