B2710 FEL won't raise/dump simultaneously

[Pete_R]

Hello
At approx 350 hrs on this tractor, this winter, most of the time, when raising the loader, and then starting the curl to dump while it was still going up, the system would hang up. Stop. You could go up, but not up and curl. The problem would go away as it warmed up this spring (although our North-East spring has hardly been very warm).

Anyway, I've used the Super UDT, and changed it per spec. What do you think is doing this? I wouldn't expect this type of problem with the low hours.

Thanks

 

[Bird]

Pete, first you need to distinguish between "curl" (rolling the bucket back) and "dump" (rolling the bucket forward). I'll guess that you have the LA401 or LA402 loader. There should be a decal on the right upright showing that it will not curl and raise at the same time; i.e., pulling the joystick back and left simultaneously. When you do that, you are opening the valve to send hydraulic fluid to the boom cylinders to raise the loader and you are opening the valve to send hydraulic fluid to the bucket cylinders simultaneously. So, what it does is move the one with the least resistance and only when it reaches the limits of its travel can the other one move.

However, you can raise the front end loader and dump the bucket simultaneously because the hydraulic pressure is raising the boom and gravity is dumping the bucket.

And welcome to Tractorbynet.

 

[Pete_R]

Hello Bird
I'm actually not new. I remember you back when I was looking for my new Kubota 7 years ago. For some reason my membership was not active (or I forgot my specific log-in) so I just signed-up again.

The fact that I haven't been here in a long time speaks well for the reliability of the B2710 tractor. Its been great.

Anyway, I used the wrong term (curl). It would not dump while being raised, a motion that must be universally used. You are saying that its gravity operated so it should work. When it was cold, while raising the loader arms, and then pushing the control arm to the left (dump) the system would just stop going up. Very annoying. Any idea why that could occur?

Thanks again.

 

[KennyV]

Pete… I’m getting confused. (not new for me)…
Bird is right you can not raise and curl at the same time… you said that is not what you are trying to do, but then you say,
“pushing the control arm to the left (dump) the system would just stop going up.”, I think you are either going the wrong direction or you are writing that you are moving ‘the control arm’ different than what is taking place…
Moving to the RIGHT is dump, to the LEFT is curl. KennyV

 

[Bird]

Moving to the RIGHT is dump, to the LEFT is curl.

Very true . . . unless the hoses are hooked up differently

And Pete, I also don't know why anything would have changed from when it was new unless the hoses are hooked up differently.

 

[Pete_R]

Kenny and Bird
Without sitting on the tractor I made a dyslexic mistake. I've used the tractor long enough to not have to "think" about how the controls work. And its the thinking that gets me in trouble....

Same Question: While raising and dumping at the same time, the system would lock up. Could this be caused by dirt in the control valves?

Again, the maintenance has been per spec, with the expensive Super UDT.

Has this happened to anyone else?

Thanks again.

 

[Bird]

Pete, I never had anything like that happen with mine, so I just don't know what might be causing it.

 

[KennyV]

Pete…
I know what you mean by thinking… it seems it use to work a lot better a lot of years ago.
This type of hydraulic system will work the least resistance circuit first, that is why you can not lift and curl… but like bird said earlier, lift and dump should not be a problem. There should be no way anything could be in the control that would cause that problem. When you just use the dump alone will it function as expected? How about just the lift alone? Everything working as you would expect? Joining the two together may show a reduced speed, but it should continue to the end of its cycle… Now after it reaches the end of it’s cycle it will do strange things, but this will only happen at the end of the travel of the piston in either dump or raise cylinder, while holding both control valves open… Has this only occurred since changing hydraulic oil and filter? KennyV.

 

[Pete_R]

I called the dealer where I bought it (1.5hr away, Chappell Tractor) and the service guy was not familiar with this problem. He did say that if you have a bunch of play in the control stick it can cause funny things to happen. He cautioned against me taking it apart because there are 5 ball bearings under tension (used for float?) that can be tricky if you don't know what you are doing. (...this sounds like, "you'll put an eye out with that thing")

Anyway, since its working better in the warmer weather (that still feels like winter in the north-east) I'll drop this thread and considering getting more information on the valve operation and repair.

Thanks for the replies.