I rebuilt the rams on my bucket truck all from tearing them down Taking measurements and ordering what I needed on line. I couldn't find any info on my boom so I didn't have any other options. That boom extension cylinder has a 10' stroke. that was a PAIN..but Hydraulics & Pneumatics is what I did for most of my time in the Navy. of course those cylinders, accumulators and pumps were a lot bigger than our stuff, most of your seals are probably quad rings with nylon backing rings and Maybe some fiber sleeves of some sort to aid in reducing wear on the seals. I would only expect to see a cup type seal on a single acting cylinder.
