Brief history, this machine was stored away where I worked and I decided to clean it and get it back in use. I've rebuilt many espresso and coffee machines before. After a tear down and deep clean the machine seemed to work fine for around 8 months. Then I noticed a leak out of the bottom of the brew chamber and the brewing punch started to push up past the gaskets and leak. Replaced both the piston gaskets and the lower brew group gasket, problem resolved.
Now the machine leaves residual liquid in the brewing chamber after a coffee cycle. So far I can run a rinse and cleaning cycle with no issue or liquid left behind. I can also make an espresso with very minimal noted left behind. When I set it to make a regular coffee the machine runs through the cycle and finishes fine but when the lower brewing punch lifts the coffee puck it is sopping and there is liquid left behind in the chamber that splashes when the punch springs back down. The full volume of coffee/espresso is made and makes it to the cup fine, the brewing chamber does not relieve all the residual liquid before expelling the coffee puck.
I have tried running the cycles with and without coffee beans being ground into the chamber and the splashing behavior is the same. I just finished replacing the relief valve and also removed the brew group and cycled hot cleaner and descaler through the lines using an external pump to ensure all lines are clean and clear. These fixes have made no change. The distributor is free of obstructions and works fine as well as all lines being unobstructed. I can get hot water, steam, run cleaning cycles, etc without any issues.
From the differences in the rinse, espresso, and coffee cycles it is as if the discharge stage of the coffee making is not as long a duration enough to allow the chamber to fully remove excess liquid. I am guessing this started to occur after replacing the seals because the chamber no longer is leaking as it was before and now the residual liquid remain.