Thanks for the advice. Removed the pump and found the roller has the mounting pin worn and the boss had rubed into the cam that actuates the pump (still mounted on the enginegear assy.) So-o-o got a new pump on order from the guys a the Benz-Bin on the way. The tip on the check valve is a another 'new' one for me thanks for that one! I just got my MB CD_ROM and did not find the vacuum pump R&R in there so thanks again. Once again this site continues to prove what a great forum it is. Good hobby, great cars and good folks, appreciate all that you all do taking the the time out to help us rookies and all alike! God bless LH