How to drain the oil in BH cylinders?

[City Farmer]

Hi all, how would I go about draining the BH cylinder oil before mounting it on my new tractor? I plan on draining/changing all the loader fluid but I know for a fact the oil in the BH has some water in it from the other machine. These are big cylinders with a lot of oil but I'd like to do it right the first time. Would air work? If so, how much pressure would it take to make it move? The backhoe is a (13') Ford 753.

 

[Richard]

I've never done it so am thinking out loud.

Attach to one end of hydraulics, push ram 100% other direction (purging whatever is in there). Reverse hydraulics to other end and now, push the hydraulic fluid (yours) out. Essentially using your hydraulic power to fill/purge the cylinder using a single hose at a time.

I once "emptied" my hydraulic fluid by doing this. I didn't really empty it but lowered the level by detaching ONE hose from my rear stabilizer and putting it into a bucket. Filled the bucket with it until the fluid was below my sight window. (the hydraulic tank holds more than the bucket I had so I needed to draw it down some)

Instead of "filling a bucket" you could fill your cylinder on one side.

That's probably how I'd do it.