W123, 300SD

Driving down the interstate on my way to a gig (I'm a musician)- First noted the BATT light come on-Which I assumed correctly to be a shot belt- but also noted the engine was overheating.This is a new (3yrs old) OEM BEHR radiator I installed) Pulled over-antifreeze all over, radiator cap intact,but the top of the radiator was tilted about 20 degrees from horizontal, tilting up at the engine side, exposing the rubber tubular gasket around the top, and the metal mesh underneath. Obviously bent up somehow and in doing so disconnected the plastic housing.

I am having problems with my Injection Pump Shutoff Valve...when I first start the car up the Valve is in the upright position..when I shut the car off it stops down and shuts the engine off. Then when I come back to restart the car a few minutes later..and turn the key to start..the engine turns over but will not start because the Shutoff Valve is down, but when I immediately turn the key off then back on, it comes up and starts the car immediately.

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?