Bucket won't drop - any ideas?

[Gem99ultra]

I have a Kubota B2410. Suddenly my bucket on the FEL won't go down. It'll go down maybe an inch in 2 or 3 minutes, but that it.

I've tried purging the system with the control lever, but that didn't seem to help at all.

Any ideas as to what my problem might be, or what to do would be most appreciated.

Jim

 

[J_J]

Check your QD'S, re-seat them.

Will it go up normally?

Is the relief activating?

Can you see the spool moving whenever you push or pull on the lever?

Do you have a gage to put in the system, and check pressure? ?

 

[MikeInEburg]

If you have 1/4 inch three-point, be sure the control is centered.

 

[Gem99ultra]

The control does not go down as it should. It seems to be hitting something solid inside the control valve. The relief is not activating either.

The 3P recently started acting strange too, i.e. it would not go down with the engine running.

The entire tractor has been serviced about 20 hours ago by the local Kubota dealer.

 

[J_J]

Does your 3pt system work correctly?

Do you see the spool move when activated?

Some valves have hard detents for things like float, and soft detents for things like regen.

Do you have your 3pt lever i n the upper most position? Should not be all the way up, just lower the lever some, and see if that makes any difference with the FEL. Has something to do with back pressure back through the system.

You need a hyd gage to test some things. Setup runs about $30 plus some QD's

Test your PRV to see if it is set correctly, usually about 50 to 100 below pump max psi.

After installing the 3000 psi gage with a QD setup, in a tee at the IN port to the FEL valve, do you have full system pressure when you push the lift lever, or retract lever?

If you have pressure with the lever activated, then move the test gage to the the tee for the cyl hoses and test the cyl hose.

 

[J_J]

This brings up the question about back pressure, and how it affects the hyd system. What I know about it is that it works against the pump pressure, and will probably affect the FEL valve or any of the other valves. I am not for sure how it affects everything. . You almost need a simulator to punch in the numbers and see the results.

For instance, with the 3pt lever up and causing the system to be relieved at say 2500 psi, will the FEL valve work correctly, or will the FEL valve work if the levers are half stroked?

What if the FEL valve uses all the pump flow to operate the cyl, how much pressure will the 3pt see?

Will the FEL valve relief activate?

 

[jinman]

The control does not go down as it should. It seems to be hitting something solid inside the control valve. The relief is not activating either.

The 3P recently started acting strange too, i.e. it would not go down with the engine running.

The entire tractor has been serviced about 20 hours ago by the local Kubota dealer.

Jim, did you actually disconnect and reconnect the quick connects as JJ first suggested? I know you don't want to do this with the loader in the air, but it should be doable and you could always wedge the bucket onto a platform while you are doing this. This just sounds like the classic loose quick connect fitting.

 

[Gem99ultra]

Just got home, but will try it and post the results tonigh.

I sure appreciate the help, whether we/you hit on the solution or not. What a great bunch of guys. Better yet, let's use the word "friends"!

 

[indianaEPH]

Jim, did you actually disconnect and reconnect the quick connects as JJ first suggested? I know you don't want to do this with the loader in the air, but it should be doable and you could always wedge the bucket onto a platform while you are doing this. This just sounds like the classic loose quick connect fitting.

yup, had exactly the same thing and found one of the QD had come undone.

 

[Gem99ultra]

Unfortunately, that didn't help. Took all the lines off, cleaned them and re-secured them. It appears that something in the control box slipped, broke, jammed, or ?

I'll take the control box off and have that checked by a professional. I'll post an update when I find out exactly what the problem was.

Thanks!

 

[J_J]

Otherwise, when you shifted the valve levers , nothing happened. Does the 3pt work?

If the pump is good, and the 3pt is working, then the pump is good.

All the spools do, is redirect the fluid, and most of the tractor hyd valves are spring centered. You either push the spool to open some lands, or pull and do the same thing.

You did not tell us if the spools were moving. Use the lever or push it in by hand.

Is the linkage/levers connected on the spool, no pins missing, etc, and is the bottom of the spool OK? Did you take the caps off the bottom of the spool. Hyd valves usually don't produce that kind of trouble of no fluid to the work ports. Did you remove the relief valve and check it?

Did you put a pressure gage anywhere and test for pressure, and if so, what were the pressure readings?

Even if the relief valve blew itself up, there would be a little fluid somewhere.

 

[Gem99ultra]

JJ, the 3P does work fine. The control for the FEL barely moves at all, i.e. <0.2 inch. It's like it's bottomed out. I did pull all of the QC's, cleaned them and re-secured them, but that made no difference. Fluid level was a little high, but I don't think it was enough to lock up the return.

I didn't tear into the control box for two reasons. a) If I discovered the problem, I wouldn't have the parts to replace them. b) I'm way over my head already on this. So, I just took the control box to a pro to check out and put a repair kit in if needed.

Hopefully I'll have some light to shed tomorrow. Meantime, I have two cylinders on my TnT that have to have seals. I'm really disappointed in the cylinders for my TnT, bought from one of our supporters, thus no names called. But they held up for less than 20 hours of tractor operation. Much less.

Hydraulics! I have a great respect for those that understand hydraulics. Unfortunately, I'm not a part of that group :-(

 

[J_J]

I am a little curious that both spools on the FEL quit. and no pressure, and the 3pt will build up pressure.

Did you try to activate the FEL valve fully, and raise the 3pt at the same time?

What should have happened, was that the FEL valve would take all the fluid, and the 3pt would get none. If the 3pt still operated normally, that means that the fluid was bypassing the FEL valve, and there is not a good reason why it would do that.

I did think of one good reason,and that is if the return port was blocked, the cyl fluid would go no where, and there would be hyd lock, and nothing would move.

Did anyone do any work on the tractor?

 

[Gem99ultra]

That's over my head. The 3P works fine. It lifts and drops fine. The bucket dumps and scoops fine. The front end loader lifts with no problems. It just does not go down. You can push up on the lever as hard as you want and it gets blocked. If you pull back, then it has no resistance. There is no fluid leakage either. This happened all at once. There has not been any sign of a problem before.

 

[kennyd]

That's over my head. The 3P works fine. It lifts and drops fine. The bucket dumps and scoops fine. The front end loader lifts with no problems. It just does not go down. You can push up on the lever as hard as you want and it gets blocked. If you pull back, then it has no resistance. There is no fluid leakage either. This happened all at once. There has not been any sign of a problem before.

Not so uncommon problem on the Kubota's, but usually affects the float position first: The cap on the end of the valve (opposite the handle/joystick) collects moisture, and the metal balls in there get rusty/corroded and won't allow the spool to move freely. The cap is help on with 2 or 3 screw, but there is a spring and 3 (I think) balls in there so be very careful when you remove it so as not to loose any parts.

Clean all the parts, grease liberally, and drill 1/8" a hole in the bottom side of the cap to allow moisture to escape.

 

[jinman]

Jim, you may have already figured this out, but if you want to get your bucket on the ground, you can loosen a fitting and let fluid leak out or you could swap the raise quick connects with the curl/dump QCs and then use the joystick to lower the bucket using the trouble free direction. Most likely you already figured this out and got your bucket lowered.

 

[Gem99ultra]

kennyd, I think that's going to be the problem... moisture corroding the check balls. I'll know tomorrow.

Jinman, I did get the bucket down though. It would drop over 15-20 minutes or so. I should have thought about swapping the lines "Could've, should've, would've" - if I'd used my head.

Again, the help and advice on here has been unreal. I do appreciate the tips.

 

[Gem99ultra]

Problem uncovered - Jinman wins the Grand Prize. Corrosion in the detent check balls of the control valve. Solved by putting in a rebuild kit instead of trying to clean it up.

Thanks so much for the very useful help guys.

 

[kennyd]

Problem uncovered - Jinman wins the Grand Prize. Corrosion in the detent check balls of the control valve. Solved by putting in a rebuild kit instead of trying to clean it up.

Thanks so much for the very useful help guys.

Jim stole my prize?:shocked::shocked:

What did I miss out on?

 

[J_J]

Did you take the caps off the bottom of the spool. Post #11

You must have skipped over that. That's OK