So we have a older Otis hydro on maintenance that was installed in the late 70s that has a cantilevered 2 stage telescopic piston. It appears to be all original and I have never seen another one like it. Anyway we are having issues with the pistons getting out of sync and the jack seals are not leaking.

Anyone ever been into one of these? Do these have check valves like the Dover/Tke or ITI jacks? I found seal kits in the Gorman and texacone catalog but that's all I can find on these jacks. Any info on these would be greatly appreciated.