Hyd flush. Any ideas oh flushing the Hyd system? Can/could it be done without harm to the pump. Would like to try this before pulling the pump. Fluid is milky and some water it appears. Sat all winter very slow now in lowering.

Thanks forthe answers and help. another question. Is there space between the bottom of the pump and the plate it mounts to?

If it were mine, I would pull the PTO shaft, drop the pump (careful, it's heavier than you might expect), get some type of solvent and a bunch of nasty rags, and something to scrape with, and do a thorough cleaning of the housing. It will be nasty, but you'll be good to go for another half-century. Inspect the pump for any damage and replace the safety (pressure relief) valve while you have it out.

Your best bet might be drop the pump, scrape it out, rinse with a bucket of diesel in a garden pump up sprayer.