Today i removed the injection pump.
There are some things i am curious about.

First one would be the relief valve. After reading some posts on different forums i deducted that this valve is located on the injection pump right here


Also here is a diagram. I am talking about element 556


When i removed element 556 it was empty. No spring or ball inside.

The misleading thing is that i also found this diagram that suggests the relief valve is located on the fuel filter housing


Second curious thing is the pump gear. I turned it to align the missing tooth with the marking on the body like so


The gear does not move smoothly. It seems to have 4 fixed positions and it just jumps/snaps into them. Is this normal? Also the o-ring (element 3 on above piture) was totally deteriorated. There was just a slight trace of rubber in the groove.