Sun will also send a few pages of instructions along with the rings. The only 'seal' that isn't included is the rubber ball located under the snap ring. Don't lose it!
Not sure if Sun supplied the orinignal Air Force pump or not.
Some will hate me for this... I honestly feel that the Benjiman pump is superior to many other pumps out there in its design concepts. Although the principals of a three stage pumps are the same across the board, much like the internal combustion engine, the Benji pump, or Air Force pump, some of the design characteristics I feel are better. For example, the base of the tube fitting. Solid brass, not aluminum; the long threading it has; the way the check seal is housed - very robust fitting; the upper end brass fitting very robust too.
Honestly, IMO, I think much of the failure issues have to do with what the factory (China?)is using to lube them for assembly. Over lubed, and lubed with the wrong stuff. I read how many people say how Sun told them 30wt motor oil, etc. Well, I was told to use nothing but silicone. That was a no brainer. Use only silicone grease or oil to assemble it. Just a dab for the orings. Get them wet then lightly wipe them off. Be sure there is no excessive build up of oil/grease in the third stage check seal area. When mine was taken apart, loads of black, nasty crud came out like a turd. Now, pumps that have been sent to me for repair, they were spotless compared to the Benji pump. Mine didn't fail, just knew it was dirty. Curiosity got the best of me, so out came the tools.
One word of caution is to NOT mar up the metal surfaces with tools;) The only part that will give you issue is the central tube used for the first stage. It is held captive by the ends which attach to the third stage tube (inner most tube). Use strap wrenches on each end and turn. Again, you mar up some of the inner surfaces, the pump may never work again!
"The majority of things in our lives are created by folks no smarter than the rest. Afterall, the world is comprised, and operated by C average people intellctually, academically, and morally. These people are often the great pioneers that set the precedent for what excellence should be."