So there is not a lot of info around about using these for hydraulics in models so i though i would share my findings, there is no wiper seal on them it seems as though there is a sleeve of some sort where the rod comes out, you can see in pics below there what looks like part of a cable tie on the bottom of the piston and a seal on the top, 3 of my rams leak around the top end cap but 1 doesn't leak at all, this maybe where my geometry is wrong and there is side load on the rams which allows it to weep, its not massive after about 40mins of running there is enough to cover your finger tip. Inside of the cylinder is finished like a mirror and the cylinder wall is 2mm thick.
I have about 10hours runtime on them now at 30bar and i am very pleased.
