Sodastream Crystal; How do I reset the two valves?

I have a sodastream crystal that isn't working properly. It seems to be the valves so I took them apart to inspect the o-rings and they were fine. Now I'm not sure how to re-seat them. There seems to be a "sweet-spot" for both of them but I cannot find it on either. From what I can see, these valves are on every model of sodastream to release the CO2 pressure when your unit gets to the right pressure which I am assuming is around 38-40psi.

The reason I took the unit apart in the first place is because it stopped "burping" and would just release all pressure through the silicon seal at the top of the unit where it seals the glass carafe and there would be an explosion of soda water everywhere, and I would have to drain the aluminum base that holds the glass carafe in place. If someone could please explain what to do here, I'd appreciate it!

Any links to parts or guides would really help!