So, I decided to replace the check valve spring from supplied parts bag and see what happens. I did 10+ pressure tests and never "stalled" the pressure during these. I pulled the check valve to see what I'd find and found oil and water, with more oil vs water. Seeing as my last few cleans only found water with zero oil, I'll take this as a good sign for now. I'll run it like this for a while and see what happens. Unfortunately, my email to Xisico never garnered a response. So much for their 24 hr. email turn around promise! I'll continue to reach Travis as well.