This unit was purchased used at an auction. It has been worked on before, obviously. This unit takes a bit of running before boom controls are active. At that point, they respond and operate very slowly. In addition, the brakes won't release until it's run some more. I replaced the control block assembly including those cartridges - they come installed. I replaced all of the hoses in the hydraulic area except for the ones that go towards the front of the machine to other items. I replaced the parking brake valve. I replaced the orbitral. I replaced the 4-way valve. I replaced the rear lockup block assembly including all those cartridges - they also come installed. The hydraulic oil gets way too hot in my opinion, also. I have not found a fix as of yet. I tested the controller pilot pressure at the port on the control block and it stays in the 100 psi area. Even after adjusting the cartridge at the control block. I am looking for anyone who might have more info. on how I might get past this point. It just got super hot and now the orbitral is toast again apparently. Any further questions, please let me know.
Dont know what machine this is but pilot pressure is too low to get full stroke. You may have a leak down stream from the (reducing valve) or (pilot pump). Also, because you are only partially shifting the spools a lot of heat will be generated as pressured oil is going to tank
It is a 2002 Terex SS1048C with John Deere 4045. It has Rexroth pump and David Brown main valve. Not sure if that will help. There aren't any leaks as far as hydraulics except for one small leak at a fitting on the main valve.