M7040 hydraulic shuttle problems,

[Confused8122]

I have a m7040hdc with hydraulic shuttle. 3000hrs. I bought used a few years ago with 2600hrs. When I got it, it was winter and cold. There was a large delay going into gear until the oil warmed up. I changed the oil and filters, useing sudt2 and Kubota filters. The delay got better, but didn't go away, reading it sounded normal. It was ok and manageable.

Fast forward to now, I use the tractor way more often, for way more things. Started making our own hay, etc.

this summer I noticed that even in the warmer temps, there is a delay going into gear. It seems to get worse when fluid is hot, but not always. It never slips, always does work. Engagement is harsher than I think it should be. Clutch pedal is difficult to use, with trans In gear, tractor stopped , let clutch out until it just grabs, and because of the delay, it is to late and engages completely, harshly.

I have changed fluid and filters again. Tried to check as much as I could, without any changes. Reading the wsm, I suspect the shuttle valve, the modulation valve or accumulate valve, but I don't know hydraulics that well . I did get some pressure gauges and checked pressures, the gauge confirms the delay, but I don't know what it means. Any help? Do I need a new shuttle valve? New clutch pack?

I took some video, I will try to post or link to. 1 is m port, 1 is r port
Pressure videos

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Thanks
Nick

 

[Tx Jim]

I tend to think the clutch control, shuttle control or modulation valve is at fault. I'll be monitoring your thread due to my owning a '11 M7040 HDC tractor with 2000 hrs on speed/hr meter that so far has performed very well.

 

[Confused8122]

Yes, those 3 valves are all built into 1 assembly. Hoping someone with knowledge and experience can confirm.

I forgot to say that everything else works good. Steering and pto work well and engages. Loader and 3 point ok. Remotes ok.
I have tried searching the site, and can find potential similar problems, but either they don't test pressures, or don't come back with a solution.

Nick