notjustair
Well-known Member
Early this past spring I had trouble with the 7800 kicking out of gear. After doing some looking and asking here I replaced the wheel speed sensor and the problem went away. All during planting it was fine, although gradually it was having svc pressure issues as I found out later. The later planted fields struggled with emergence in dry weather and it looked like the tractor wasn't putting out the down pressure it should.
During haying it blew one of the door cylinders clean apart and the clutch was wildly erratic. It also could not keep the baler door shut without me riding that unit every minute or so. I rebuilt the one other cylinder (it was not leaking internally, but I thought I would cover all of the bases) and the door stays shut like normal when run on the 4440. Then it began to kick out of gear when the clutch was used. If I downshifted the power shift all of the way to neutral without the clutch it was fine, but push in the clutch and pull it to neutral and try to back out of the windrow and it would flash transmission trouble and I would have to shut it down and restart it.
After some looking online I realized the hydraulic fluid wasn't returning to the sight glass like it should while the tractor was running. It was staying in the front end and heating up. There is very little showing in the sight glass (even after running hours) while it is running but returns to the full mark within 30 seconds of shutting it down. I cut the air pump line and it is sucking air from the differential case like it should. I can both blow and suck air through the back hose so I know the line for the air pump isn't plugged. The air pump vacuum changes with the tractor rpm and works all of the time.
What should be my next place to start checking?
During haying it blew one of the door cylinders clean apart and the clutch was wildly erratic. It also could not keep the baler door shut without me riding that unit every minute or so. I rebuilt the one other cylinder (it was not leaking internally, but I thought I would cover all of the bases) and the door stays shut like normal when run on the 4440. Then it began to kick out of gear when the clutch was used. If I downshifted the power shift all of the way to neutral without the clutch it was fine, but push in the clutch and pull it to neutral and try to back out of the windrow and it would flash transmission trouble and I would have to shut it down and restart it.
After some looking online I realized the hydraulic fluid wasn't returning to the sight glass like it should while the tractor was running. It was staying in the front end and heating up. There is very little showing in the sight glass (even after running hours) while it is running but returns to the full mark within 30 seconds of shutting it down. I cut the air pump line and it is sucking air from the differential case like it should. I can both blow and suck air through the back hose so I know the line for the air pump isn't plugged. The air pump vacuum changes with the tractor rpm and works all of the time.
What should be my next place to start checking?
