Rick,
The old white style that you had to unscrew before pumping was really a bear. I always had to use pliers to unscrew it. I called Haynes to get a manual for our car and they never made one. I went to the dealer to order the chassis manual for the W116 and they said it was no longer available, so I decided the next closest thing would be the W123. It is nearly always identical to my car. The funny thing is, my dealer recently gave me a new CD Rom Model 116 Service Manual Library. I was flabbergasted. Upon examining the CD Rom I realized that the photos/descriptions were almost all the same as in my W123 chassis manuals.