Hello everyone I'm new here in this forum; I'm from Ecuador South America. In my job we have some equipment to support facility operations in some of our customers. I'm working now in a JLG 800A articulating boom lift. We have some liking from the internal seal in the center rotary coupling of the equipment, we asked to the local dealer about this issue, after they ask to factory they recommend replacing the coupling. We bought a refurbished one and now we want to change it, but we have some questions: 1. Is the coupling only manages the hydraulic fluid to the wheels motors? 2. Is necesary use some support on the base of the boom to prevent the boom fall down when we disconnect the hydraulic fluid lines? I really appreciate your help with these problems. BR Alfonso
The rotary swivel joint only supplies oil to the wheels for rotation and braking. That swivel joint is up in the center of the frame.the boom has holding valve on the cylinders. You can raise it up to gain better access from the top if needed. Now if you mean the swing motor you do not have raise at all.some machines have ball shut off valve by hydrualic tank.just remember to open them when you are down .because it only takes second to take out the pumps from no oil to them .Have lot of caps and plugs on hand .use different colors of wire on the hoses and where it goes on the swivel .when you have old swivel on bench .swap over fittings one by one to new swivel. Make sure to use all new orings . Take your time .don't rush .if you do mix up hoses it will drive you nuts.
Thanks for your answer tool_king. Y think that I need to buy a new oring kit and some markers to don't miss any hose.
You will have orings on both sides of the fitting .One side flat face other side oring boss. Don't go cheap on not replacing the orings it will bite you in the ass later on. And if you loose one the flat face ones for the hose and don't notice .you find out real fast when go to use it. Use colored zip ties or if you can get phone cable wire .It makes great wire for marking lines .Has lots different colored wire in it.
they are pretty heavy! Use a strap and crane if you are able to from the top to help it down once you take the bolts and hoses off.
Take some pics of the orientation of the swivel and the hose connections. After you've removed it, busted it apart, and proceed with the re-install, if there's any doubt of how it was fitted, a picture is worth a thousand words.