Combines Hyd soumd

[slipclutch]

We had a 7720 combine that made a lot of noise and it was the removable shield under the seat that was vibrating very loudly. Bent it slightly and it was fine...makes me wonder if that could be it because if you lean one way it quits. Also might check to make sure the cylinder variable speed valve spool (lever beside throttle) is not sticking. This is the same valve that your unloading auger swing out is controled from. If it sticks it causes the main relief valve under the cab floor to be activated all the time and that in turn causes great deal of oil heat.

 

[Deerebines]

Well, been my experience that the unloading auger, reel lift, and header lift are all tied in together in the same string of valves. The header lift is primary....unloading auger secondary....and the reel lift is final. So with that said.....that is a closed center system and I'm beginning to wonder if the valve that stays closed till pressure is needed has broken a spring or the ball detent is gone or something along those lines and the pump is running full bore and you are hearing your bypass screaming it's tail off. Where is the pump on the 7720IJ My 6620's was under the seat and the 8820 was over by the radiator in the engine compartment. If it's under the seat perhaps part of your vibration is coming from that shaking and hammering......I don't know. I'm tossing ideas here is all as I've never dealt with this before but I would tear that pump down or put your hand on it. Run the combine for say 10 minutes and don't touch a single hydralic function....if that pump is hotter than hades than it's just circulating fluid and something went to crap on you inside of the pump. In a nutshell....it sounds like your pump has internal problems. Should be able to test it on the machine somehow but I don't know for certain.....Deere tech could fill you in on that. lIke I said....I don't know for certain.....just trying to toss you some ideas that maybe you didn't think of If you find it be sure and tell us......You have my curiousity up now as to what's going on.

 

[guru]

both deerbines and slip clutchs answers are well worth looking at because u say the noise stops when u lean to the right and stays when to the left points me in the direction of the unloading valve has the auger moves from it craddle..and saying it stops or is better when the auger is unload positon....make sure that all your controls are returning to the neutral postion that is all controls used for hydraulic functions has somtimes one will cancel out another and cause relief valves to pop..then it is a matter of elimanation use the machine or start the machine and use one fuction at a time aand see if it comes back make sure you give it time not just wait 30 seconds or so hope it is of some help would like to hear of what it is when u find it