My power steering sometimes looses its power assist when at low speeds like when pulling into a parking stall. I sucked the old stuff out to where the pump tank was empty and got about 20ozs out of it. I refilled it with Amsoil power steering fluid and it helped some but still looses its power assist. One person told me to take the return line off and start the truck to pump all the fluid out. They explained there is still a lot of old fluid in the system and most likely still causing the problem. They told me to run ATF through it until the system was flushed and showing clean ATF while flushing it. Just wondering if this is correct way to do this or is there another way? Thanks again TDR!