I have a John Deere 950 with a third-party loader of unknown make. I've been experiencing a hydraulic problem, and I'd like to ask for any suggestions. I have the JD service manual, and think it's quite good, but when it comes to the hydraulics I just don't have all the special test equipment that seems to be at the core of the troubleshooting section.
The FEL and 3pt operation has been slow, jerky, and getting worse over the last few weeks. This past weekend operation was so very slow that I didn't even try to take it out and do any work. This is Alabama, so it's pretty hard to blame it on cold. Besides, I've used the tractor with snow on the ground and the ground itself frozen, so temps in the 50s shouldn't be causing any trouble.
Here's what I know, in order that it comes to mind:
1. Slow and jerky operation raising either the FEL or 3pt (box blade). Lower just fine.
2. Dumping and curling are also slow and jerky. Sometimes when dumping the bucket just stops and won't go any farther. If I curl and dump, curl and dump, it will eventually go on past that point like it should.
3. On a couple occasions when I put the bucket on the ground and then try to dump, an operation that normally picks the front wheels off the ground with no trouble, I notice that the bucket forces the loader arms up instead of raising the tractor. Then if I lower the arms, there's a long wait when it seems like nothing is happening, but then it will very slowly lift the front wheels.
4. I don't have a float position on the FEL.
5. I've tried just sitting and running the FEL and the 3pt up and down, thinking maybe to work the problem out. This has grown less and less effective (it takes longer and longer to get to smooth operation). Weekend before last it never did smooth out in 2-3 hours operation. Transmission was warm to the touch. Transmission is also the hydraulic reservoir on this tractor.
6. I use JD's recommended fluid, and the level's where it should be.
7. New fluid and filters about 50 hours ago. That's supposed to be a 600-hour service interval.
8. I don't hear the relief valve open while these symptoms are occurring.
9. I have noticed a hissing sound, and this weekend found that it seems to come from the hydraulic pump, or at least that area.
10. System relief valve is at the rockshaft.
11. Someone suggested air in the system, but I can't figure how it would get there, because I haven't had the system open except at the dipstick since before I serviced the filters 50 hours ago. And if air were in the system, I thought all the raising and lowering would work it out. Instead things are getting worse.
12. Engine starts right up and runs fine, doesn't seem to be loaded or anything.
That's all I can think of. Any hints, suggestions, questions of symptoms I may have missed?
Thanks,
Steve
The FEL and 3pt operation has been slow, jerky, and getting worse over the last few weeks. This past weekend operation was so very slow that I didn't even try to take it out and do any work. This is Alabama, so it's pretty hard to blame it on cold. Besides, I've used the tractor with snow on the ground and the ground itself frozen, so temps in the 50s shouldn't be causing any trouble.
Here's what I know, in order that it comes to mind:
1. Slow and jerky operation raising either the FEL or 3pt (box blade). Lower just fine.
2. Dumping and curling are also slow and jerky. Sometimes when dumping the bucket just stops and won't go any farther. If I curl and dump, curl and dump, it will eventually go on past that point like it should.
3. On a couple occasions when I put the bucket on the ground and then try to dump, an operation that normally picks the front wheels off the ground with no trouble, I notice that the bucket forces the loader arms up instead of raising the tractor. Then if I lower the arms, there's a long wait when it seems like nothing is happening, but then it will very slowly lift the front wheels.
4. I don't have a float position on the FEL.
5. I've tried just sitting and running the FEL and the 3pt up and down, thinking maybe to work the problem out. This has grown less and less effective (it takes longer and longer to get to smooth operation). Weekend before last it never did smooth out in 2-3 hours operation. Transmission was warm to the touch. Transmission is also the hydraulic reservoir on this tractor.
6. I use JD's recommended fluid, and the level's where it should be.
7. New fluid and filters about 50 hours ago. That's supposed to be a 600-hour service interval.
8. I don't hear the relief valve open while these symptoms are occurring.
9. I have noticed a hissing sound, and this weekend found that it seems to come from the hydraulic pump, or at least that area.
10. System relief valve is at the rockshaft.
11. Someone suggested air in the system, but I can't figure how it would get there, because I haven't had the system open except at the dipstick since before I serviced the filters 50 hours ago. And if air were in the system, I thought all the raising and lowering would work it out. Instead things are getting worse.
12. Engine starts right up and runs fine, doesn't seem to be loaded or anything.
That's all I can think of. Any hints, suggestions, questions of symptoms I may have missed?
Thanks,
Steve
