Tractor Had the Hiccups

[aledobud]

I bush hogged about an hour this morning on my 1533 and after I finished, I was idling a little before cutting off the tractor. The tractor started doing a little jump every few seconds. Both the cutter and the loader would jump. It didn't matter what RPM. I seems more like some kind of hydraulic surge rather than an engine miss. I cut off the tractor, re-started and the jumping stopped. Any idea what causes this? I googled the symptoms and all I read was a little different from what I was seeing. I have a video, but couldn't upload it. If it repeats, I'll contact the dealer.

 

[Sysop]

Best bet would be to upload it to youtube or similar, then provide the link here.

 

[aledobud]

Here is the video:

 

[kthompson]

Wife's family had a Ford 601, 1962 year bought. Those tractors had this so common think it was like about 12 a minute was called normal. Do not remember the exact reason other than the issue was with the seals for the 3 pth. It is possible an issue with the lift cyl seals. Have you checked your oil level?

 

[Spanner]

Watch the rear implement and notice it drops slightly then the tractors position control activates to reset the lift you have selected.
I think if you set the mower down on the ground the hiccuping stops?

 

[k0ua]

Yep, you have a problem with the 3pt leaking down, and it is a bad one. The position control returns the cutter back to the original position after the leak down.

I have seen this in a lot of old tractors with worn out 3pt valves. BUT your tractor is near new. It should not do this. It might be a piece of debris caught in the valve. In any case, this tractor needs to be loaded on a trailer and returned to the dealer.

 

[Sysop]

^^ what he said...

 

[aledobud]

Would it be the position control valve that is leaking, which I think is external, or a bigger problem inside the case? Also, any idea why it would have stopped doing this after I shut off the tractor then re-started?

I'm going to use the tractor until it consistently repeats before I take it in. My experience with dealer shops is they have to make it happen to believe there is a problem. I had to take my 3 month old Toyota Tundra in three times to convince them my idler pulley needed replacing.

 

[k0ua]

Would it be the position control valve that is leaking, which I think is external, or a bigger problem inside the case? Also, any idea why it would have stopped doing this after I shut off the tractor then re-started?

I'm going to use the tractor until it consistently repeats before I take it in. My experience with dealer shops is they have to make it happen to believe there is a problem. I had to take my 3 month old Toyota Tundra in three times to convince them my idler pulley needed replacing.

are you sure it has stopped? Did your raise the 3pt with the cutter (weight) on the 3pt?

Perhaps maybe a piece of debris has passed thru the valve and it is OK now.. All hydraulic valves leak. It is just a matter of how much. The job of the position control is to maintain the position of the implement on the 3pt as the valve or the single acting cylinder bleeds down and the 3pt lowers slightly. The feedback mechanism of the position control opens the valve to apply flow to the cylinder to bring it back to where it was. This maybe occurs once every few minutes in a good new system. So rarely that you don't notice it. But your video seemed like in 5 seconds there was enough leakdown that the position control was operating the valve to restore position. And that ain't good.

 

[k0ua]

Also the problem would likely be worse after the oil is hot, not when the oil is cold. Hot oil is thinner and metal to metal valves would likely leak a bit more when hot. As I said above they ALL leak, but it is a matter of degree.