Orlando has a post on his GLA site detailing with pictures how the Clippard solenoid valves are now being manufactured over seas and the quality has gone to crap. I agree. There are far higher quality valves then the clippard now I would look at Parker first (that's my thread above about two of them dieing. I purchased an incorrectly spec'd valve) and then maybe Burkert. Just make sure you're buying one that is spec'd proper for the job.
Not sure if people are describing the same problem. I believe my issue was from the piston not sealing or closing the hole completely. Cleaning restores it to normal and or the spring is too weak, or the piston is not aligned and rubbing on the way up and not fully closing the hole to block CO2.
I'm still operating fine since my cleaning and lubricant I added (described earlier in the thread).