08 3720 Cab 3 Point Hitch Drops about a 1/2 inch per minute?

[nmu98]

I was working on some stuff in the barn before I went out and did some cutting. I had my MX5 up in the air completly so there was significant weight on it. About every minute I would hear the 3 point hitch raise about a 1/2 inch. That does not seem normal? Might a I have a metal shaving in some valve? How can I correct this? I have done a full fluid flush about 15 hours ago.

 

[AKfish]

I was working on some stuff in the barn before I went out and did some cutting. I had my MX5 up in the air completly so there was significant weight on it. About every minute I would hear the 3 point hitch raise about a 1/2 inch. That does not seem normal? Might a I have a metal shaving in some valve? How can I correct this? I have done a full fluid flush about 15 hours ago.

It was rising not lowering?

I've seen Ag tractors that the 3pt would lower and then the pump would engage and the 3pt would rise back up again. Kinda surge up and down in a rhythmic manner.

Is that's what's happening?

AKfish

 

[nmu98]

It was rising not lowering?

I've seen Ag tractors that the 3pt would lower and then the pump would engage and the 3pt would rise back up again. Kinda surge up and down in a rhythmic manner.

Is that's what's happening?

AKfish

Sorry, Yes, that is what is happening. It will go down and surge back up. It slowly goes down for about 60 seconds. So slow that you would never see it, then it lifts itself back up.

 

[Spudland_Dave]

Sounds like the feedback rod might be out of adjustment...when I was fiddling with mine trying to get the "full range of motion" I inadvertenly adujusted it so it did the same thing as you describe...

OR, the more I think of it, you might be right, a seal or metal filing might be the problem. The Feedback rod is there to keep the TPH in the raised position when the control lever is raised...

 

[AKfish]

The feedback adjustment is how we resolved the Ag tractor problems.. (at least for a while - cause the pump was getting tired and finally had to be replaced).

I'd check it first and see if the locknut is loose and readjust if necessary.

If you had some foreign material in a line - you should have symptoms. Pump working harder to lift, slower response time to lift, likely noisier - hissing, maybe a squeal in the pump. And with a load - the pump may go into bypass - without fully lifting the implement as it normally should.

AKfish

 

[nmu98]

I have none of the symptoms Fish.... Everything works normal. I have a month left on warranty and for what it pains me, I think I am going to send it to the dealer for them to document and hopefully not make it worse......

 

[AKfish]

I have none of the symptoms Fish.... Everything works normal. I have a month left on warranty and for what it pains me, I think I am going to send it to the dealer for them to document and hopefully not make it worse......

That's a better course of action.. if it's under warranty - definitely!

Good luck and let us know how everything turns out.

AKfish

 

[nmu98]

The dealer has not been over to pick up the tractor yet and i was messing with it last night after i cut some of the field. At idle, witht he MX5 in the air completely, the 3 point would drift down slowly (very slowly) over a few minutes, and then pick up about a 1/2 inch.

If I put the tail wheel of the rotary cutter on the ground, there is no drop at all. It makes me wonder if its due to the amount of weight that is put on the hitch and due to the fact that it is so far behind the tractor.

Long story short, I am having a hard time sending the tractor to the dealer for a problem that might be normal. Could anyone else test this out or let me know if thier machine does this?

 

[radman1]

Some leak down is normal with a 3 pt attachment on the lift arms. A little drop with a heavy mower over several minutes is normal. (That is the beauty of positon control on the 3 pt.) If you are getting drop with no attachments or light attachments over a few minutes, then that is probably excessive. It is a function of how good the hydraulics valves and components are. Our ag tractors can hold at nearly the same level for hours and probably days with the tractor off. My CUT would probably creep to the ground with a mower in couple of hours.
It is the same with the FEL hydraulics/valves.

The question is what is considered excessive. JD and dealer will argue that it is normal. They usually have some standard to consider what is excessive but it is probably a broad range. I had what I felt to be excessive leak in the tilt of my Toolcat under heavy load. Took me a little debate with my Bobcat dealer to see it my way. They replaced the tilt valve and now it holds steady for a long time under heavy load. IMHO, the amount of drift with your mower on the 3 pt is probably ok.

 

[JD755]

Can't comment on possible problems with the position feedback loop, but JD does have max leakdown specs for their tractors. On my 755 the spec is 0.079 inches in one minute with 770 pound weight on the hitch. Spec is at end of draft arms. Of course this is with the engine off.