FEL Valve Notchy or Sticky

[Crank Shaft]

I have a B2320 that I got new back in 2014 and it came with a factory-installed joystick FEL valve which I used only to operate a power angle snowplow.

About 5 years ago I got a used loader for a good price and installed it myself. It worked great but gradually the FEL valve has gotten harder and harder to operate smoothly.

By smoothly, I refer to the ability to feather the control valve for very slow movements of the bucket. The valve now seems to want to operate like a light switch; Full On or Full Off. This applies to both bucket curl and bucket lift.

Anybody have any idea what might be wrong? I used to be able to feather the movements, but now it is next to impossible.

Here is what I have done so far:

1) Made sure all valve linkages are well oiled or greased.
2) Drilled tiny oil hole where the valve return springs reside and injected spray lube in the holes.

Despite this, the joystick is notchy or sticky, making smooth application very difficult. Not cool when lifting engine blocks or heavy items.
Thanks for any and all advice.

 

[oldnslo]

Can you disconnect the joystick linkage from the valve spool? If yes move the joystick to see if it is now moving freely. If yes the try to manually push and pull on the spool. If this is notchy the end caps covering spring assembly will probably need to be removed and components cleaned.

Only other option is some contaminates got in the valve passages and scored the spool or valve bore which is unusual but possible. You might be able to carefully remove the spools from the valve body and polish spool and hone valve bore but in doing so could increase internal leakage so loader drifts under load.

 

[Crank Shaft]

Thanks oldnslo,

Access to the valve is difficult to say the least. Fender, seat and loaded wheel have to be removed which I don't mind doing if I have a reasonable hope of success.

 

[oldnslo]

Does the joystick mount directly to the valve or are their push-pull cables between joystick and valve? If cables these are known to corrode and bind over time causing exact problem you are describing.

 

[Crank Shaft]

No cables, the joystick mounts to the valve itself.

Here's a photo of the valve internals. It looks like if I unscrew part 36 and 25 then I will have access to both detents, springs etc. If I do this I sure hope I can get it back together correctly while laying underneath the tractor.

 

[rScotty]

No cables, the joystick mounts to the valve itself.

Here's a photo of the valve internals. It looks like if I unscrew part 36 and 25 then I will have access to both detents, springs etc. If I do this I sure hope I can get it back together correctly while laying underneath the tractor.

That's good about not having cables to deal with. BTW, how accurate do you think that drawing of the valve compared to your valve?
From the drawing, it looks to me like parts 36 & 25 are housings for the parts that give that spool valve its detented "float" functions.

The stange thing about that drawing is there seems to be a detent for "float" position in both the FEL lift arms and also in the bucket rotation. That's unusual, because float is usually only in the lift arms. Do you know if your control valve ever had float detent positions for the loader arm AND for the the bucket?

The reason I ask, is because sticky FEL control valve operation is rarely anything that you can or should try to fix inside the spool valves or inside the valve body.

Sticky FEL control valves are usually fairly easy to fix. It is probably one of two things.
Eiither crud and lack of ube in the external levers and pivots that let the joystick move the spool valves .....or it could be ccrud and lack of lube in the spring & ball detents for the float assemblies (36 & 25)

Try the top levers first, but if that doesn't work, you should be able to take those parts 36 & 25 off and clean them up. Float detent assemblies are vented, so they do get dirt and rust inside. Just be prepared for a lot of spring loaded balls and small parts when you unscrew them.
Luck,
rScotty

 

[Crank Shaft]

Thanks rScotty. The parts diagram for the valve parts came right out of my service manual so I assume it is accurate. My owner's manual indicates both spools have float which seems odd but maybe for smoothing gravel it is of a benefit to float the bucket lift as well as curl???

 

[rScotty]

Thanks rScotty. The parts diagram for the valve parts came right out of my service manual so I assume it is accurate. My owner's manual indicates both spools have float which seems odd but maybe for smoothing gravel it is of a benefit to float the bucket lift as well as curl???

I've heard that some valves had both floats, but have never used one. Sounds like yours does. You will be able to tell for sure when you crawl under there and look at the valve. I'm curious; if floating the bucket is a benefit you'd think more valves would be built that way. But no real downside either way.

If you do take the float detent off, you may be surprised at how much rust that mechanism builds up inside. Steel wool it.
And don't loose those parts! Unscrew that detent assembly with a bucket or something over it.

 

[SPYDERLK]

Do the spools return to center by themselves when you ease back on the control force you apply to the joystick, or do you have to push the joystick back to center? Does the action feel the same when the engine is off - no pressure?

 

[Thomas]

Have you tried good spraying of WD40 on valve? might have slight build.

 

[greenie]

I've gotten around jerky FEL movements by feathering the dump very slightly while raising or lowering the lift/drop - in other words I bleed off pressure by lightly opening another FEL function.

 

[Lineman North Florida]

When is the last time that you changed your tractor hydraulic fluid and filters?

 

[Crank Shaft]

When is the last time that you changed your tractor hydraulic fluid and filters?

About 20 engine hours ago.

 

[Crank Shaft]

Have you tried good spraying of WD40 on valve? might have slight build.

Thanks. I used Fluid Film sprayed generously into every single joint on the valve. I did this while working the joints. I can confirm that in this case it is not a lubrication issue, it has to be something internal.

 

[Crank Shaft]

Do the spools return to center by themselves when you ease back on the control force you apply to the joystick, or do you have to push the joystick back to center? Does the action feel the same when the engine is off - no pressure?

Yes spools will return on their own when engine is running. I believe they feel the same when engine is not running but will have to confirm that tomorrow. I've thrown my back out and it's pouring rain outside, so I am house bound until me and the weather recovers.

 

[rScotty]

I've gotten around jerky FEL movements by feathering the dump very slightly while raising or lowering the lift/drop - in other words I bleed off pressure by lightly opening another FEL function.

That's not uncommon. That's an old trick you discovered, and it does work sometimes.

With cheap or just plain worn control valves that start to get internal leaks it can help to throttle way down or divert some of the hydraulic flow so that the bucket is not so jumpy. On our JD 310 backhoe/loader I'll throttle down, use both boom & bucket controls together, and even turn the steering a bit to reduce the flow...and it is still more jumpy than I'd like. And the JD controls are usually some of the best....Not these, though.

On our old Kubota, the control valve is so accurate it is easy to move the bucket a tiny fraction of an inch with accuracy. Some of what you get with controls has got to be just dumb luck.....or not.

About all you can do with really worn controls is replace them with aftermarket. There is no way I know of to renew the tight clearance between the spool valve & the control block bore.

rScotty

 

[Lineman North Florida]

About 20 engine hours ago.

10-4 sometimes neglected fluid & filter changes can result in sticky loader operation, but obviously that's not going to be the case with your tractor with a fresh fluid & filter change.

 

[ruffdog]

About 20 engine hours ago.

What fluid did you use? Some (wrong) fluids may swell o-rings and make valves sticky.

 

[Crank Shaft]

What fluid did you use? Some (wrong) fluids may swell o-rings and make valves sticky.

Kubota spec UDT.

 

[34Willys]

If this is notchy the end caps covering spring assembly will probably need to be removed and components cleaned.

Had this happen on my hydraulic log splitter. The lever was difficult to move either direction and would pop over to full on. I removed the rear cap and found some water and slight rust. Disassembled, cleaned, and reassembled. Adjusted detent and operates perfect.
Watch those little detent balls when disassembling. Three of mine ended up in the gravel before I got to the bench. Luckily, I found them.
Hope your back is feeling better.

Patrick