I have a 1995 hyrang by simon-telelect GH75PBI that we are working on, all 4 outriggers are controlled by one control on one when they are put down by the control they hold pressure and are able to lift the truck, when outriggers are lifted by control the rear outriggers will drift down and we are able to lift them back up by hand. initially we were thinking it could be a valve issue however with them holding when lowered by the control, but we aren't sure. Wondering if anyone has any ideas or maybe a manual and can look it up. We would also be interested in purchasing the manuals if possible
Not familiar with that particular model, and if I'm reading this right, you're saying when you raise the outriggers into the stowed position the rear outriggers will drift back out. If that's correct, it depends on whether your outrigger cylinders have a single holding valve or two holding valves. Don't recall the brand/model because it was years ago, but I've run across digger derrick rigs that only had a single holding valve to lock the cylinder in the extended position only. Once you retract them, if the piston seal of the cylinder is bad it will drift back out because the control valve isn't totally internal leak free. Check where the two hoses connect to the cylinder and see if there's one or two cartridge valves fitted in that area.
On second thought, even if your cylinder has two holding valves those outriggers can still drift out if the piston seals are bad. You need to find out what hose connections you have, JIC, ORFS (O-Ring Face Seal) and get two plugs and caps for those fittings at a hyd hose shop. Once you have those, retract a faulty cylinder fully and stick a floor jack under the outrigger pad to hold it there. Disconnect the hoses where they connect to the cylinder, mark them so you don't cross them up on re-connection. Stick a cap on the fittings on the cylinder. Now release the jack and wait. If it drifts down, you've got failed piston seals on that cylinder.
Thank you for the information I will pass along to my tech!