I recently drained, removed and cleaned the power steering pump(outside only) and resevoir. After re-instalation I filled the resevoir let the car run for a short time then drove it around. I now have no power assist anymore. There has been no change in fluid level from pre-drive to post drive. Is there possible air in the system or the hoses at the pump backwards(if able)? The symtoms seem strange after being driven. Any ideas would be welcome.