Brookside1954, Wow, Mil-H-5606! Haven't heard that since I left Naval Avaition. But don't put that in you hydraulic system. Hi Los use Dexron series automatic transmission fluid. Find the earliest series you can, ie, III, IV, V or even VI. I recently had my cylinder rebuilt and they serviced it with VI. Don't quote me, but 5606 is a natural petro product and is used with synthetic seals==tranny fluid is synthetic and is used with natural seals. Keep an eye on how much fluid amasses in that line and for safety, look for a hyd shop that can rebuild that cylinder. my rebuild was about $200.
Tree