I have a 4850 powershift with the old 8 speed trans. Earlier in the summer, the hydraulic system started starving and upon pulling filters and screen, found the old woven style brake linings were shedding out and plugging the system. Cleaned the screen and new filters and back in the field maybe long enough to finish the summer. No luck. System starved out again, but this time, the filters were plugged with antisieze looking goop in the filters. Likely brake disc(s) being ground up. The problem which now has arisen and is much more serious is the transmission it loading down in most of the speeds. Does anyone here have experience with these transmissions? In reverse; 1 and 2 work, 3 and 4 lock down. Forward; 1 and 2 work, 3,4,5 and 6 lock down while 7 and 8 are still working. All the nonworking speeds have C2 clutch in common. I am hoping the control valves are getting stuck from the metal particles in the system as it was working fine before the linings let loose and it hasn't been under heavy load since.
Well, yeah, something is getting stuck, might be valve spools, might be the clutch piston. Deere made a lot of machines with the inboard wet disk brakes, and they're a great system EXCEPT when they're used to destruction. I'm sure you had no way of knowing but the brake lining material plugging the suction was your machine's desperate cry for help. I have some experience with this from the construction side. I hate to tell you but that "anti-sieze looking goop" is ground cast material from the plate that the brake linings were riveted to and they're way softer than the steel brake plates. Once the linings fail and go away the brakes are metal on metal and that lovely silver metallic fluid is literally EVERYWHERE throughout the transmission and the hydraulic system including steering and brakes. This stuff acts like powdered metal when it fills a gap, if it's something that can move and compact it the silver particles practically weld stuff in place. We did an old 510 backhoe, I begged the owners to let me take it to the shop after finding brake lining fibers in the suction, but no, they ran it until it laid down and died. Even after completely stripping it down to the bare main case and cleaning and rebuilding everything including all the cylinders and valves, we were still seeing silver in the filters a couple years later. I hope you're luckier but I'm afraid you're in for a long painful road to get that old girl back up to snuff. Sorry man. :IMO
I heard it crying and knew what it was going to take to fix it but try telling the owner who really really needs it :badidea and I don't have the time for it at the start of hay season. JD changed the brake linings from the fiber to a compacted paper as I installed them on a 4650 back in the winter. The metal sludge compacting and setting up is something I haven't thought of. I wonder if doing a running flush with diesel would do much washing or would the ULS stuff get me in trouble with lubrication.