Hydraulic question on a Kubota M 6800

[HCJtractor]

Thanks guys. That all makes sense and I expect that is what's happening. This drill is new and I really have not even hardly moved it yet. It was delivered to my dealer to unload, and all I have done is hooked it up to just get a feel for how responds and how my tractor handles it. This week end I plan to load it on my gooseneck and take it home to the shed. So my "seat time" with this drill hooked up is about 1 minute, just enough for me to notice the FEL issue. As I load it and move it further, I certainly will see how it responds and try those tips you guys suggested. And certainly, I plan to minimize lifting it very high or for very long. This drill was designed to usually be operated with a tongue as a pull type, but also has the ability to be 3 point connected. Unfortunately, the tongue was discarded in the past, so I bought it w/o it. From what I can see from my limited use so far, I either need to make a new tongue, or just operate it without lifting it. My first challenge is loading it on my trailer, but hopefully I can just drive it up the ramps with no or minimal lifting. I am just waiting for the weekend so I can have plenty of time to do this without rushing, and when I can take a buddy to help me monitor loading it. I will keep you posted on progress, but your explanations make sense now and I expect that I was overloading my 3 point as you guys suggested. Thanks for your interest and knowledge!

 

[slowzuki]

Just try lifting it partway first. This may keep you off your relief valve. 3 point mounted is nice if you are planting any wet areas, your draft control can be used to get traction if you start to spin by picking up the drill. Towed type the tractor has less traction and the dolly wheel often sinks in badly.

To the poster who's hitch doesn't leak down, it does. Just slow enough you don't notice. I remember using an old Ford 3000 that would bump the 3 point every 2-3 seconds when you had any kind of weight on it to maintain its position setting. The old 3 point was very leaky. With a heavy load on it the hitch valve stayed open and the other hydraulics on the tractor stopped operating due to the priority valve.

 

[MikeB44]

I hooked up my new grain drill to the 3 point hitch and lifted it. Weighing in at 3000 lbs, it was a load. I also tilted it forward with the hydraulic top link to gain more ground clearance. I then tried my FEL and it would barely move, very slow response. When I sat the drill down, the FEL seemed to be normal. I suppose the hydraulic system was overloaded. Is this a normal response? I was lifting it to load onto my trailer, and as I go up the ramps, it would be nice to be able to alter the FEL just to get clearance and balance..

I had a similar situation on loading my L3010 onto a trailer for the first time. FEL on the front, bush hog on the back. The FEL suddenly stopped working, and it took a bit to find my issue,:ashamed: - but it was due to the 3pt hitch control being all the way up. We were concerned about dragging the bush hog on the road and trailer and didn't notice we had the controls all the way up (basically keeping the hydraulics running on the 3pt). Once the FEL was "acting up" in front of us, we didn't think about the 3pt causing the problem behind us (or actually the 3pt control arm beside us).

I would be interested in knowing if the weight of the drill at a lower 3pt setting still causes the same issue with the FEL.

 

[J_J]

Once you get the 3pt raised up and release the handle, or push the handle into neutral, the fluid flows through the valve unimpeded, pressure on the hyd system drops and the loader should work normal as there is no back pressure on the FEL valve.

The 3pt cyl is essentially closed off in neutral

I really thought I had explained this earlier.

 

[HCJtractor]

Thanks JJ. Your explanation was good, it was brain that was bad! I appreciate your taking the time to share your expertise. Just curious, but how do you know so much about hydraulic systems?? Are you an engineer or just have lots of experience?

 

[MikeB44]

I really thought I had explained this earlier.

You probably did and I apologize if I confused or strayed the subject.

Once you get the 3pt raised up and release the handle, or push the handle into neutral, ... the loader should work normal as there is no back pressure on the FEL valve.

My L3010 doesn't work this way. If I pull the handle all the way up and release it, my loader will not function until I push the handle down (maybe an inch?). Possibly this is a defect in the proper operation or operator. (Note that releasing the 3pt handle for me means that the handle stays in the position I released it in, unlike my loader control which returns to center when released.)

As far a neutral position, I have not seen that marked in my 3pt hitch control (just marked with numbers 1-8), nor been instructed in the term for the hitch operation. I may have to pull out the manual to review.

Thanks

 

[slowzuki]

You just can't see how its working. You move the position control and it shifts the valve away from neutral until the hitch has finished reacting to attain the desired position. When it approaches the position it shifts the valve back to neutral. When you go all the way to the top with your lever, sometimes the dealer hasn't set the limits exactly and the hitch can't attain the position you've told it to attain so it can't shift back to neutral.

An adjustment can fix this.

You probably did and I apologize if I confused or strayed the subject.



My L3010 doesn't work this way. If I pull the handle all the way up and release it, my loader will not function until I push the handle down (maybe an inch?). Possibly this is a defect in the proper operation or operator. (Note that releasing the 3pt handle for me means that the handle stays in the position I released it in, unlike my loader control which returns to center when released.)

As far a neutral position, I have not seen that marked in my 3pt hitch control (just marked with numbers 1-8), nor been instructed in the term for the hitch operation. I may have to pull out the manual to review.

Thanks

 

[J_J]

MikeB44,

If you have a gage in the hyd system, it will read no pressure or very little pressure when the 3pt or any other valve is in neutral, meaning the 3pt valve is not using the fluid, except to pass the fluid to tank/reservoir.

There is no reason that the loader should not work, as it has priority in the flow path of the fluid.

That being said, if the 3pt is in relief mode, the loader might not work correctly, as some have experienced.

There is nothing wrong with the system, that is just the way some of the hyd work.

Once the 3pt is set to a position, there should be no pressure in the hyd flow path, and if you use the loader, it should work normally.

 

[Egon]

You just can't see how its working. You move the position control and it shifts the valve away from neutral until the hitch has finished reacting to attain the desired position. When it approaches the position it shifts the valve back to neutral. When you go all the way to the top with your lever, sometimes the dealer hasn't set the limits exactly and the hitch can't attain the position you've told it to attain so it can't shift back to neutral.
/QUOTE]

Had that happen to me a few times with the Kubota B7100.

Nice simple explanation.:thumbsup:

 

[cougar21300]

It should be easy to determine if the 3 point is still trying to lift your drill even though movement has stopped. Raise it as far as it will go, shut off the settlement rate valve entirely, and then move your position control down a bit. If the loader works then you likely have reached the limit of the lift capabilities. If the drill isn't high enough at that time to give you the clearance to climb up onto the trailer there is a simple trick you can try. Use your loader downpressure to lift the front wheels off the ground, this will likely also ground the drill and remove some of the weight from it. While the loader is still holding the front end up, open the settle valve, again raise your position control, and then close the settling valve again. When you lower the front wheels to the ground your drill should hold the higher position until you open the settling valve.
If this works but you can foresee constant problems with insufficient 3 point lift, you may want to have your system relief pressure checked. Kubota allows about a 10% tolerance from spec. If your tractor is 10% low, and you have it readjusted to 10% over, you will notice a BIG difference