I didn't like the control pattern of my cat 307b excavator (right joystick forward moved the main boom down and moving it back raised it). I like for the right joystick to pull in and push out the second boom. So, I switched the cylinder hoses at the cylinders and now the controls are right, but when I move the left stick forward to lower the main boom, it lowers an inch and then stops and you can hear the hydraulics straining, but if at the same time, you push forward on the right stick, it will lower. It's like the right stick is providing some relief to the cylinder and allowing it to retract and lower. Any ideas? There are two additional hoses on the Main cylinder that I didn't touch and I'm thinking somehow they are part of this problem.
I can't really tell you where to make this change as I'm not familiar with the 307B, but I can tell you with certainty you need to change your connections at the cylinders to their original configuration. On any excavator, doesn't matter the brand or the model, to make this change you have to swap pilot control hoses that come from the joysticks themselves. That's the part I can't advise on just what hoses to swap, but that's where the change has to be made, otherwise you confuse the hydraulic control computer on the machine.
There are load lock valves (anti drift valve) in the boom that are controlled by the pilot signals as willie59 states. Apparently you have gotten used to the John Deere backhoe control pattern instead of the standard excavator controls. Put you cylinder hoses back where they were and then trace the pilot hoses from the valve. They usually go to a big block with a bunch of hoses and switches attached. Mark the hoses with something and then find your arm cylinder hoses. Mark them as well before you change anything. Good Luck
Just changing hoses to change the control pattern and not doing any research on how the hyd. system works seems like it could be a really expensive lesson.
Thanks for the feedback. I dont think and i hope nothing is damaged. Can someone. Provide. A little more guidance on where to swap the hoses for the controls. No more experimentation on my part from here on!!
TBH I would suggest engaging the services of an experienced hydraulic systems mechanic.
Cheap way would be to make a diagram, give a little crack to your pilot line, then actuate (the guessing part) your joystick, second person will see where it's coming out. Then you mark that hose with colored tape or multiple zip ties and write the function of that port on your diagram
I haven't looked at a 307 but as a rule the cat excavators have a pilot hose junction under the cab. The hoses should have tags labeled R1 R2 R3 and R4 for the right joystick and L1 L2 and so on for the left joystick. You will want to swap R1and R3 with L1 and L3.