hydraulic jack rebuild

If kits are still available for older hydraulics then it is possible that it can be done.

I rebuilt old Happi-Jac hydraulics on on old '94 pop-up... those had square tube not the round like you show. I am not familiar with the brand/ model in the picture. Mine were easy to do but the solid round steel rod that extended and was very pitted one one. I emery-clothed it as best I could knowing it would scar the seals and begin to leak again. The rebuild did solve the leak for the duration of my owning that particular caper

Back when I did the rebuilds, the cost for four kits was about $60, not sure what they might be now if available. You might want to perhaps factor cost to buy, time to invest and the potential that existing condition might prohibit a rebuild. If the lift rod is severely pitted then it might be fruitless.

The cylinders themselves and especially the one that does not build pressure have no fluid leaking from them. There is no resistance when pumping so the seals or “ chevrons” as they refer to certain seals have failed. The unit is used occasionally for desert trips so money spent needs to be on the lean side. I don’t mind tearing them down and rebuilding them.

Guessing by whats left of diamond decal they are rieco-titans

https://riecotitan.com/store/productlist.php?search=1&cat=11

Kind of amazing you can still get all the parts for the old hydraulic jacks .... but not the newer Attwoods.

Ya I'm in need of a cover for one of my Atwoods. There's a set of bevel gears on amazon for $5,450. I have no appreciation/understanding of a company buying another then abandoning completely any support-

One older thread on hyd jacks...
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26408204.cfm
Apparently jacks filled while retracted, red ATF fluid.
Reico titian has downloadable instructions if owner doesn't have. The owners manual outlines priming if jack 'stuck'. The other, maintenance manual, for rebuilding.
http://www.riecotitan.com/instructions.php