I have had 2 GTP's that had a rather large front skid plate (plastic) under the subframe at the front. It blocked off all underneath access to to areas like the bottom of the rad. If the end tanks are leaking or the hose has a split or the overflow is busted at the end tank, coolant can drip down & sit on the skid plate until you start throwing these pigs into a few corners at which time the coolant flies off the skid plate and mother nature sucks it back. Might be a slim possibility but I have experienced it when my overflow hose leaked & all the air being thrown around from the pulleys & belt was spraying **** all over the place. If the coolant he sees is localized to only the power steering pump area then I would retract my suggestion unless he has two simultaneous leaks?