The new buffer seal (blue) is completely different looking than the old seal (brown). I'm assuming it's an upgrade and that's how it should be? The new buffer seal should be installed so the black ring faces the rod seal, correct? I can't find the torque spec for the bolt that holds the piston, does anyone know what it should be torqued to? Thank you!
Serial number or know one can help with a torque spec if you want exact numbers
5PC06012
Torque for bolt that holds the piston - 820 +/- 75 ft. lbs. Most seals go brown after they have been exposed to hot hydraulic oil for an extended period of time. I suspect the buffer seal you removed would have originally been white/cream in colour believe it or not. Correct buffer seal orientation is as per the diagram below. 13 is the buffer seal. I couldn't find a good illustration for your machine. This illustration is from a 416D lift cylinder, but the seals will be very similar in design if not identical. EDIT: Bugger, beaten to it by Mark ..........
Thank you both!
clean it well and use locktite as well.
Got it back together, everything went well. Working on repacking the boom swing cylinder now. Hate to ask for another tq spec, but would anyone know the tq on that bolt? And I read somewhere to not heat the bolt because it will damage the spring? Will it break loose without heat? Thanks
You're starting to get up there now. Torque for that bolt is 1340 +/- 90. I've never pulled one of these apart myself but looking at how it all fits together I have difficulty in undertanding how heat could help loosen the bolt considering the arrangement of the rod, piston, & bolt. Looking at where the spring is located I can't see how heat would affect it though. It appears as though the only alternative to a cylinder bench would be to manufacture a wrench from some 1" plate, then with a load of weight on the wrench beat the lving c**p out of the head of the bolt with an FBH to shock it loose. I see that the later machines the rod is threaded and the piston is held on with a nut that is only torqued to 680 ft.lbs. - much easier to get off. your machine - 416B