The steering box on my 280E is leaking fluid. It appears to be from the seal near where the pitman arm attaches to the output shaft. My local Mercedes specialist tells me that this is a time consuming and expensive repair involving a strip down and replacement of the (many) seals within the box. Although I intend to get this done in the next few months, is it worthwhile in the interim flushing the system and adding a power-steering stop leak product to the new fluid, or is this just a waste of time?