I gave just today purchased jlg 450a lift. It has a bad hydraulic leak when trying to activate the lower boom cylinders. I cannot see the source of leak, but it seems to be coming from the area of lower end of bottom boom. The lower two cylinders do not work....probably because all the fluid runs out on the ground when you try to activate them. I have not found any "good" drawings to assist a newbie in figuring out how to get to that area. I suspect it is a busted hose, but gettingvto it seems to be the 64 dollar question. Any help appreciated. Stacy
All. I found this problem. it was a busted hose down near the bottom, but in a place you could hardly see or get to. Replace the entire hose. Problem solved
For future reference, JLG has all manuals (Operators, Service, and Parts) for their machines available on their website for free. I just downloaded all of mine foe a 45HA and they have been super helpful to me.