We have a 2021 JLG 1055 telehandler that is experiencing intermittent "no lift", plugged in analyzer, module is seeing joystick functions. Swapped LIFT UP with TELE OUT electrical connection at the MCV and received the same results. We swapped a known good EPRV solenoid into the LIFT UP at MCV, same results. We will be going back to the unit(its 2 hours away) to do some pressure tests and more troubleshooting. As we are just an end user and not a dealer JLG wont talk with us. Anyone have any suggestions to help isolate this issue?
UPDATE: Isolated issue to bad counterbalance valve on main lift cylinder. Must be replaced with entire manifold assembly as no serviceable parts are available. After installing the new assembly i tore down the old assembly and found a severely rusted and broken spring. As this is a low hour machine with no signs of hydraulic contamination and zero signs of corrosion anywhere else in the manifold as these components live immersed in hydraulic oil its likely it was assembled with the rusted component when new. Something to check for if anyone else starts seeing these symptoms. It would only lift at full throttle and if bouncing the joystick, occasionally it would shift the poppet open enough to allow flow and lift to work.