Review on ECCPP 21-5196 Power Steering Pump Fit for Subaru Impreza, Forester, Legacy, Outback (2010-2014) by Justin Fletcher

When properly pumped it seems to work well. To prime, replace the pump first and before installing the belt, fill the reservoir with fluid and rotate the pump pulley by hand for about a minute to avoid a dry start. Then install the belt, raise the front wheels and start the engine. Spin the wheel lock a few times until the squeak goes away, check the fluid for bubbles and continue until bubbles appear in the reservoir, refill if necessary. The pump works as it should, no leaks.