Frustrated !!!
- Thread starter Fred Joe
- Start date
Welcome to TBN. 
Briana03
Elite Member
WELCOME to TBN
I moved your thread to the Parts/Repairs Forum.
I moved your thread to the Parts/Repairs Forum.
kebo
Elite Member
- Joined
- May 16, 2006
- Messages
- 2,910
- Location
- Lexington, SC
- Tractor
- 2001 John Deere 790 4x4, bar tires
On the older tractors, most of them have/had inspection ports on the side of the trans. tunnel. If yours has one, the SOP is to pull the cover off, and inspect it while it's running, and operating the lift up & down with a heavy implement on it. Note: This is an inspection port only, not a "stick my finger inside it while everything is moving" port. So word to the wise, if you stick a finger inside it, you might not get it back out.
But, looking through the port with mirrors and lights, see if you can spot a fluid leak from perhaps the standpipe (if it has one), or from around the piston. I know you changed the ring and seal but maybe the cylinder is worn and is letting excess fluid get by it? Also, have you monitored the hydraulic pressure as it lifts, and then while the implement settles back down?? If the pressure stays up, while the implement settles back down, that will tell you the pump is probably ok. If the pressure goes down with the implement, then the problem is likely in the pump. Good luck.
But, looking through the port with mirrors and lights, see if you can spot a fluid leak from perhaps the standpipe (if it has one), or from around the piston. I know you changed the ring and seal but maybe the cylinder is worn and is letting excess fluid get by it? Also, have you monitored the hydraulic pressure as it lifts, and then while the implement settles back down?? If the pressure stays up, while the implement settles back down, that will tell you the pump is probably ok. If the pressure goes down with the implement, then the problem is likely in the pump. Good luck.