Originally Posted by bobs
Our cars use Pentosin in the power steering system, which is a synthetic fluid. If you top up the reservoir with regular fluid you will most likely have the seals in your steering system begin to leak. I would recommed you do a complete system flush and refill with Pentosin.
I second that......if you use a petroleum product in something meant for synthetic, there's a good chance the rubber parts in the system will begin to swell and leak!