I borrow my neighbor's post pounder, it has long hoses and a fair sized cylinder on it, so it holds a good bit of hydraulic fluid. He has one of those funny green colored tractors so he uses different hydraulic oil. Should I be worried about mixing whatever hydraulic oil green tractors use with my orange tractor oil when I use his pounder? I was thinking I could hook up the supply side to the pounder and cycle it while I collect the output of the return side in a clean bucket, that would allow orange tractor oil to displace green tractor oil. Or am I being too ****...