Loader Bleeds Down

[jimainiac]

The loader on our Kubota L3830, will bleed down when left up. I'm wondering what I could do to make it stay up better. It has been this way since new but never really bothered me that much, as I drop the bucket down when I'm finished with the tractor. It was a problem today, though, because I was using the loader with pallet forks on, to raise shingles up to the eaves while shingling a roof. After sitting a while, the arms would lower, and the pallet, which had been level, started to angle down. I would like to remedy this if I could. I would think the problem is with the loader control valve not sealing well enough. Has anyone had any luck addressing a problem like this?

 

[RoyJackson]

The loader on our Kubota L3830, will bleed down when left up. I'm wondering what I could do to make it stay up better. It has been this way since new but never really bothered me that much, as I drop the bucket down when I'm finished with the tractor. It was a problem today, though, because I was using the loader with pallet forks on, to raise shingles up to the eaves while shingling a roof. After sitting a while, the arms would lower, and the pallet, which had been level, started to angle down. I would like to remedy this if I could. I would think the problem is with the loader control valve not sealing well enough. Has anyone had any luck addressing a problem like this?

There are a couple threads in the Safety forum addressing relying upon hydraulics.
There were a few responses discussing using some kind of mechanical device that fits over the cylinder rod between the cylinder and clevis (thus holding the cylinder open). Since I don't use my loader to hold anything up, I didn't pay too much attention to those posts, but you might want to take a look.

 

[kennyd]

Short of buying an industrial type loader with very expensive poppet control valves and pilot operated check valves on the cylinders, I don't think there is anything your going to do about this. Just the nature of the beast for CUT's.

 

[flusher]

The loader on our Kubota L3830, will bleed down when left up. I'm wondering what I could do to make it stay up better. It has been this way since new but never really bothered me that much, as I drop the bucket down when I'm finished with the tractor. It was a problem today, though, because I was using the loader with pallet forks on, to raise shingles up to the eaves while shingling a roof. After sitting a while, the arms would lower, and the pallet, which had been level, started to angle down. I would like to remedy this if I could. I would think the problem is with the loader control valve not sealing well enough. Has anyone had any luck addressing a problem like this?

I have a 2005 Kubota B7510HST with the LA302 FEL that sort of has the opposite problem: the FEL stays put and doesn't bleed down. But the 3pt will bleed down after a few hours.

According to TBN threads that I've read, the 3pt bleed down is a common problem for Kubota CUTs. It hasn't been a problem since I can close the 3pt hand valve under the seat to keep it from bleeding down.

 

[Soundguy]

Could be anything from a slight bypass inthe cy;s.. to the spool valve. Spool valve construction could be anything from metal on metal with close tolerances or oring... both can leak...

Soundguy

 

[638]

Buy a set of quick disconnects (male & female). Put a ball valve between them and put it in the circuit that is bleeding down. Raise your load and then close the ball valve. If the load then drops, the cylinder piston seal needs replacing. If not, then the control valve is worn.

ron

 

[john_bud]

It's easier to buy a plug and put it in one cylinder port (you actually need 2 plugs, one for each side's cylinder). Same deal, it will tell you if the leak is in the cylinder (common and cheap to fix) or in the valve (un-common and very expensive to fix).

Cylinders are fixed with readily available seal kits. Will be at or under $50 per cylinder and about 1 hour of your unskilled labor. The valve would need to be replaced. (it can be repaired by honing out the bore, truing the spool, plating it up and machining it to fit the new bore size - but it's probably cheaper to replace. But not cheap!!)

jb

 

[638]

Its kind of hard to raise a load with plugs in the cylinder ports.

ron

 

[john_bud]

True, but we always did that first ;-). Then blocked the bucket, set the plugs and did the checking.

Not as nice as the QD's you listed but easier on the wallet (but harder to use)

jb

 

[638]

How did you get the blocking out from under the bucket?? Then how did you lower the bucket to reinstall the hoses?? Just pull the plugs??? Sorry, but my way is much safer, and a lot easier. Can also be used for the other circuits. And if it is the control valve can be used to lock the bucket in the up position so that he might be able to finish the job at hand.

ron

 

[jimainiac]

Thanks for the replies, I've been so busy finishing the shingling job I haven't gotten to the computer. It was a great help using the loader to get the shingles up to the roof, even with the slight bleed down. My wife didn't like lugging shingles up the ladder. I like the idea of the quick connects with a ball valve, seems like that would take care of the problem, just like the locking valve for the 3PH.

 

[john_bud]

How did you get the blocking out from under the bucket?? Then how did you lower the bucket to reinstall the hoses?? Just pull the plugs??? Sorry, but my way is much safer, and a lot easier. Can also be used for the other circuits. And if it is the control valve can be used to lock the bucket in the up position so that he might be able to finish the job at hand.

ron

Ron,

settle down... There is more than one approach to a fix. Just because I have used a different one, isn't an indictment of you.

As a diagnostic aid, blocking the port with a simple plug is very cheap and easy to do. Having a chain fall, cherry picker, or even floor jack is all you need to lift the bucket. It's not ment to be a permanent fixture to the machine.


Have a great day,
jb

 

[Soundguy]

Seems like a jack and timber would work for getting the block out of the way.

Lower the bucket.. well.. unless it was a pilot check valve system.. seems like actuating the joystick back to the 'lift' side, witht he tractor not running should let the oil exhaust as in SA fashion.. depending on the specifics of the spool in question.

Safer? that's Arguable. His way can be made safe.. with patience . Easier? perhaps.. then again.. if you have little or no money.. then plugs become 'easier' than qd's and a valve...

In short.. both work.. both can be done safely.. or unsafely.. and cheaply and/or easilly.. it alldepends on the mechanic.. and the thing on his shoulders holding up his hat.

Soundguy

How did you get the blocking out from under the bucket?? Then how did you lower the bucket to reinstall the hoses?? Just pull the plugs??? Sorry, but my way is much safer, and a lot easier. Can also be used for the other circuits. And if it is the control valve can be used to lock the bucket in the up position so that he might be able to finish the job at hand.

ron

 

[slowrev]

Is the problem for sure in the valve assy ? This can be / also is cause by cylinder piston seals leaking...Oil blowby so to speak.

 

[BTDT]

I don't know how hard it would be on your machine, but could you switch the hoses at control valve that go to bucket cylinder with hoses that go to loader lift cylinder and see if problem switches places. With hoses in this setup, if it was control valve, your bucket would leak down and your loader wouldn't. But if loader still leaks down, it's probably internal to the loader cylinder.

 

[Steve_Miller]

BTDT,
Beat me to it, this is what I did to prove it was my control valve.

Steve