On friday 2/27/14 i replaced the two cylinders and re attached the lines that raise the screen box. THATS ALL I DID. since then, when i activate any other lever that has nothing to do with the screen box, ( such as jacking legs, fold/unfold side belt ) the screen box raises. the lever for the screen box only has one direction, UP. to lower it, it simply lowers buy its own weight.
I'm not familiar with the hydraulics on this specific machine but I would recommend following the pressure hose off the control valve that lifts your screenbox to make sure it isn't Tee'd into any other circuit or anything. Another possibility is that the pressure hose for whatever reason is connected into the return manifold. As far as I'm aware most return lines all go into the return manifold, which is in turn pressurised. If the screenbox lift ram CV pressure port is connected into the return manifold there may be enough pressure in the system to raise the screenbox while using any lever more or less. Sorry I can't help much more :/
Also just throwing ideas out there, no specific knowledge... So it worked fine before then, but the cylinders leaked? or? I'd look into the spool for that circuit, take the cap off, pull the spool out. You didn't use teflon tape, did you?
I got it. all i did was replace the valve and now it works like new. the mcCloskey is a good machine, the one that constantly burns my ass is the fintec 1107. theres no trouble shooting section in the 3 manuals i have. when i was hired 8 months ago, i was trained on the equipment for 2 days then i got a strong pat on the back and told to make stone. so i totally appreciate everyone's help in here..... THANKS