In addition to the other replies ;

Because I personally have opened quite a few of these and _every_single_one_ has had a worn out spring ~ not only do coil springs have a finite life span but the check ball sits directly in the end of the spring and moves constantly, this wears the open end of the spring until it fails ~ many I have seen were paper thin and crumbled when I touched them .

As mentioned, older German cars/mechanics/engineers all assumed you'd be endlessly under the hood cleaning, adjusting and testing things .

A Mechanic I know was trained in Germany, by Mercedes but thinks they're '****' because of this aspect ~ he drives a Lexus and will trade it in long before it reaches 80,000 miles so he sees no point in doing the things we Diesel Heads consider normal .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better