Last year our 7120 went 160 threshing hours before the warning came on, blew it out and it lasted again another hundred or so, blow it out and it was good until the end of harvest. Strange that some can be so bad and the next so good. If i had your problem I would be tempted to put a vertical stack with a turbo pre cleaner on top high enough to suck mostly clean air. Sucking dirty chaffy air from around the combine just doesn't make any sense.

 

Have u had a look at the new machines at all to see the changes? Besides the way they changed sucking from bottom of radiator box to the top they also put in some simple rubber guards to stop the screen sucking from under the side panel doors. At the bottom of the housing they extended it out a little and put a fold of light rubber that pushes up against the side door when closed. This stops any air from inside the door which is full of chaff getting sucked up by the rotary screen. Simple change but seems to work really well.
Ill try take pic for u and put up

 

I assume the venturi from the exhaust is working properly? They block up quick when these aren't working.

 

Our 2388 was doing the same thing, and I thought the seal looked good also. After further review though, it was wore and not hitting on the top, and the seam had an ever so small crack. After replacing the seal, we can go 2-3 days in wheat without an issue. Hope this helps.

 

There is an aircleaner update get it works fine, i think the kinda copied how Deere does it to fix it.

 

thanks all, the first year I had the combine wasn't much of a problem, last year had more wind and very dry harvest, so perhaps this year will be different. They did a update for the 8120 and higher but told me it wasn't or couldn't be done to the 7120's

 

Is this the Jeff I think I know?