Recovery Pump Rebuild Questions...

Greetings all,

I am new to the cls game, and recently received a used MKIII and accessories. I understand the CPS TR600 recovery pump isn't sealed and will lose vacuum, more so after the piston seals begin failing. This unit is a couple years old, but only used maybe every 6 weeks. When pressure testing for my first run, I was seeing a quick fall off and isolated it at the pump. I later tested each side independently under vacuum, approx -28"hg. The inlet side lost 20"hg in 5 minutes. I can't imagine this is acceptable... The outlet side lost roughly 5"hg in 5 minutes, and seemed to slow as the 5 minutes passed. After reading posts here, I see piston seals are often the culprit on the inlet side. Short story long, is this an easy rebuild? I'm very limited on time and despite a cursory web search, have not been able to find any info on the process.

I'm also considering buying a second pump as a back up, or full time and move the TR600 to backup. I see the TRS21 seems to get good reviews here. Older posts talk about the Appion and the Promax, though I don't believe either of those are spark proof. I should note, I will not be running more than 200-250 grams of material a month though this unit. Are there any pumps I'm missing that would do the job as well or better that the TR600 or TRS21 in that price range?

Thank you for your time!

How are you connecting your gauges? Vacuum is a poor indicator of pump condition as they are not meant for vacuum service.
A better way is to hook up a set of standard refrigeration gauges to the inlet and outlet ports and fill the pump with compressed air through the gauge manifold. Shut off the inlet valve and watch for a pressure drop. There is always going to be a drop but if it is slow don't worry about it.

As far as rebuilds, it is fairly easy once you know how. Cleanliness is critical. Clean everything with acetone. The piston seals take a bit of finesse to get them on. They need to be gently stretched to get them onto the piston. I usually cut the old ones to get them off, but be careful not to scratch the grooves as this will cause leaks.

Peace.

RB