Ok this is what I've come up with.
Originally I wanted to use these seals, little more robust, a little better sealing. But,,,,, the od is just slightly larger than the id of my tube. And they are just too big to be squeezing into a 1/4" shaft hole. (Id is .25, od is 1/2") things got more complex and seeing what others use I'm going to go with the o-rings and one x-ring for the seal.
The tube is necked down just so I have more allowance for bolt pattern for the cap. Piston has three rings, bolted with m4 screw. The rod seals are internal but the three are what go inside. Trying to have the last oring close to end to act as much as a dust seal/wiper.
This is cylinder top. This is just a mock (f-up) up of what will be made. The shaft hole is too large, I'm using 1/4" shaft and making the passage hole .30. So a couple hundredths of clearance. Does this look, sound, seam, like it will work? The rings will be loaded, squeezed into the groves when shaft is installed making the right seal. I don't know what to expect as I'm not familiar with these pressures or anything whatsoever with hydraulics. I did test one on a blind hole with some coolant and about standing on it when seal let loose and shot coolant to ceiling. I'm thinking that should be good for 100-150 psi? It's a dozer so I don't think I need the pressure like an excavator. What bar/psi am I among for ?