Hello All, The machine JLG 600 AJ Now when you take the boom up then the boom comes down say 1 ft in 3 to 4 minutes. This is when both the main boom as well as the tower boom is lifted but when booms are taken up & the basket is at 20-25 ft then d boom doesn't come down it is only on height that the boom & the main boom Cly ram goes down. There was a pipe leakage which we have solved. There is a slight leakage in the main boon small fulcrum cylinder main boom cylinder little ahead of the fulcrum is okay The holding valve o rings okay. Your advise n prompt response shall be very much appreciated. Thanks, Ali
After the boom drifts down the 1 foot, will it stop drifting or will it continue to drift down? There was a sizable oil leak. Was the hydraulic oil level refilled to full? If the oil level is low, the pump can start cavitation and introduce air into tho oil. This can result with the condition you describe. Check the fluid level and be sure to check for air in the oil.