I bought this machine a few months ago.When you lower the main boom,it bounces,like if it were on a spring.I cracked the plug at the bottom on that hyd. cylinder .Some air came out but not much.I have changed all the hyd. oil to case spec's but still does it. Note:before I bought it the owner told me they changed the controls to cat controls by switching the hoses. I have operated other manufacture of backhoes and never seen a problem like this. any help appreciated :Banghead
If you are talking about when you first lower it from the very top, that's a Case. I have owned a '91 sk for 14 yrs, and have operated many older and newer 580s, and they all do it.
Switch the hoses and put it back to the original pattern and the bounce should go away. If you want the the other control pattern it can be done with linkage. The boom and dipper valves have different valving inside them for the function they are designed to run. When the hoses are switched to make the other pattern it goof up the operation of both functions.
Thank you guys for the responce.Funny but I ran into a guy in the coffee shop and he said the same thing you said Goose.The valveing is different for the main boom than the second boom as you might say.He use to be a machanic on cases.Whats the chance of meeting someone like that.Thanks again.....Sam