I replaced the high / low switch and reverse gear in John Deere 4020 tractor. Once I replaced the high / low switch and the reverse switch fell over 2 weeks later.
The hydraulics in John Deere 4020 are bled when the bucket is raised and slowly lowered when the controls are released. The loader will only pick up the front of the tractor by rolling
I was waging when my tractor John Deere 4020 began slowly losing the revolutions. Finally he went to idle and then turned off. I changed and purged the system but I still could not get it to work.