3-Point Hitch Engaging 3point hitch with FEL raised caused engine to get really rough/stall

[rmtygart]

I have a Kubota BX2200, and am pretty new to the game. Runs great, no problems until a friend raised the FEL to the top and operated the 3ph at the same time. Engine suddenly got really rough. Once it was shut off and the FEL lowered, and the 3ph raised again, it ran fine. Dealer says it was because the 3ph was "in detent" and the two implements were "fighting each other". Hasn't recurred. Dealer says that those two, the FEL and the scraper attached to the 3ph need to be operated separately, not both at the same time. Anybody experience this?

 

[Jim Nelson]

How about that,another guy from Fallbrook!! I've had 4 different Kubotas and they all have different quirks and what you are experiencing is common.These small tractors just don't have the sophisticated hydraulic systems that you find on construction equipment but they sure beat the heck out of a scoop shovel and wheelbarrow.

 

[rmtygart]

Thanks Jim! Good to know there's another Fallbrook guy on here. Good to know that this is not particularly something to worry about. Sounds like you have plenty of Kubota experience. I ran big tractors as a kid, but it's been a long time, so things take some getting used to again. Just got this BX2200 last week from Pauley. It was a trade in. Might go with a new one eventually, but overall I'm pretty happy with this one right now. Mostly use it for moving mulch around the property. Have to get together sometime.

 

[Panik]

Dealer says it was because the 3ph was "in detent" and the two implements were "fighting each other".

Hmmm I've got a BX2360, basically a more recent model of the BX series, and as far as I know my 3-point doesn't have a detent. Out of curiosity do you remember what rpm the engine was at when you had the rough running issue? I've been wrong many times before, but I have to wonder if the rpm's were to low to support operating both the FEL and 3-point. Just something for you to think about when you're running your tractor. Either way have fun! :thumbsup: They're great little machines and mine's become pretty much invaluable.

 

[rmtygart]

Hmmm I've got a BX2360, basically a more recent model of the BX series, and as far as I know my 3-point doesn't have a detent. Out of curiosity do you remember what rpm the engine was at when you had the rough running issue? I've been wrong many times before, but I have to wonder if the rpm's were to low to support operating both the FEL and 3-point. Just something for you to think about when you're running your tractor. Either way have fun! :thumbsup: They're great little machines and mine's become pretty much invaluable.

He did have it a just above an idle, so that may have just been too much for the engine to handle at low rpms. Other than that one little incident, it has performed perfectly. This seems to be a great little tractor, and perfect for manuevering around our orchard, but big enough to do anything we want to do. Thanks for the info!

 

[aczlan]

What the dealer is explaining is that as the pressurized fluid is filling the "lifting" side of the loader cylinder (to lift the bucket), it needs to "vent" fluid from the "lowering" side of the cylinders. That fluid goes downstream through your rear remotes (if equipped) then through the 3 point valve, then into the tank.
If the lever for the 3 point lever is in "raise" position and the 3 point is all the way up, the only way for the fluid to get to the tank is by getting to 2000ish PSI and going through the relief valve.
That causes the loader and the 3 point to "fight" each other.
Note: This should ONLY happen if you are trying to move the loader and the 3 point at the same time.


Aaron Z

 

[rmtygart]

Thanks for the detailed explanation. I'm still getting to know this machine and that is a great help. I will be sure to not let anyone operate both of those at the same time.

 

[Panik]

Aaron my thanks as well for the hydraulic's explanation. My apologies Rmtygart about the bad info on my part.

 

[jimpen]

Well I have a Mahindra Max25. If I have the 3PH lever all the way to the top (for lifting the MMM) it causes the FEL to essentially operate in reverse. The bucket goes down instead of up. The arms are very slow to rise. But if I put the 3PH lever down farther than the very top the issue goes away.

So it sounds like it is a universal problem.

 

[aczlan]

So it sounds like it is a universal problem.

Yes, its due to having the hydraulics run in series (in an "Open Center" system). The way around it is to use a closed center system, but those are very expensive.

Aaron Z

 

[rmtygart]

Panik, no problem! Thanks to everyone for sharing the info. This is the best way to figure these things out.

 

[jim44]

I must say, I have never run into this problem. That being said, how do you operate the loader and 3PH at the same time? I don't think that I have ever had occasion to even think of this, much less try it. I have difficulty operating one at a time usually..........

 

[rmtygart]

I must say, I have never run into this problem. That being said, how do you operate the loader and 3PH at the same time? I don't think that I have ever had occasion to even think of this, much less try it. I have difficulty operating one at a time usually..........

Good point! I wouldn't do it either. It was a friend "trying things out" :thumbdown:

 

[Gary Fowler]

I did that a lot when I was using my box blade to loosen up the dirt and FEL to scoop it up. I would be loading the dirt from the previous pass that was loosened with BB scarifiers with the FEL and dragging the box blade loosening up another pass and also dragging a load of dirt. When I got to where I was dumping, I pulled the 3 PH lever up then immediately raised the FEL to dump its load of dirt.
Lots of time when you may want to raise both at the same time and there shouldn't be a problem other than maybe a slower reaction time but certainly not a problem with stalling the engine. I think something is not plumbed right in the hydraulics if it is doing that. The hydraulic pump should not be enough to stall the engine before it goes into relief. As a matter of fact you shouldn't even hear a change in the engine as it goes to relief.
If it was my tractor, I would find another model on the dealers lot and see if it does the same thing and if not, make the dealer fix what ever is the problem. Even if other models do the same thing, that isn't right. The dealer set up mechanic might be doing something wrong when he sets up the FEL hydraulics.

 

[aczlan]

Lots of time when you may want to raise both at the same time and there shouldn't be a problem other than maybe a slower reaction time but certainly not a problem with stalling the engine. I think something is not plumbed right in the hydraulics if it is doing that. The hydraulic pump should not be enough to stall the engine before it goes into relief. As a matter of fact you shouldn't even hear a change in the engine as it goes to relief.

I'll have to disagree. The OP said that it was "just above idle" when this happened. I interpret that to be 1500ish RPMS The BX2200 has the D905 engine which makes under 12HP at 1600RPM (per: DieselEngineMotor.Com - Kubota Diesel Engine D905 ) If the hydraulic system was making 3GPM at 1850PSI, that takes 4HP, at least 1/3 of the available HP.
That will put a significant load on the engine and could stall it out.

Aaron Z

 

[J_J]

Here are some facts you should know.

With all valves in series in an open center hyd system, the first valve has priority and that is only if it is using all the pumps flow.

When that valve is maxing out the pumps flow, the excess fluid in flowing over the relief valve to tank.

There is no fluid available for downstream use. No 3pt, no nothing.

When the valve is only using only half pump flow half that flow is available for downstream use.

Now, here comes the problem. When the 3pt is not maxing out the cyl, the hyd work normally.

When the 3pt maxes out the cyl, the flow is diverted over the relief valve to tank. Now, the fluid backs up into the FEL valve and causes problems. It could blow seals, and flow into the FEL cyl.

If the 3pt relief valve is set to say 2500 psi, this 2500 psi is now trying to work against the resistance from the valve flow and from the pump.