Goofy 3 point action

[trudie1]

OK I am going to try this again as I am really getting tired of fighting this problem......Kubota L3000DT issue started when a hydraulic hose from the joystick to the chassis wore through and started dumping hydraulic fluid all over. I replaced both the supply and return lines (carefully so as not to cross them up). Ever since, I can't get the 3 point to lift at all until I roll the front bucket up, then the 3 point lifts as normal. Anybody ever encounter anything like this??? Appreciate anyinsight.

 

[kennyd]

Is the fluid foamy looking by chance?

 

[DiskDoctr]

Or is the fluid low? What did you refill it with?

- JC

 

[mmurphy]

Are you also saying that valve has to be held in bucket roll up position before 3 PH works?

 

[DiskDoctr]

Are you also saying that valve has to be held in bucket roll up position before 3 PH works?

Good question. Let me split that one up.

1. Does the 3 PH work when curling the bucket (FEL valve activated)?
2. Does the 3 PH work after bucket is curled and is held against the relief?
3. Does it have to be curl, or does it work the same when dumping, too?

- JC

 

[trudie1]

Nothing showing foamy at all, Thanks

 

[trudie1]

Fluid filled completely with Kubota UDT fluid per specs, Thanks

 

[trudie1]

I place the 3 pt lever in the raise position and nothing happens until I roll the FEL up. No other FEL operations have any effect. Thanks

 

[jinman]

What everyone seems to be hinting at, I believe, is that you are having some type of loader valve problem. On my tractor, the loader valve (joystick valve) must be in neutral for the fluid to flow to the 3PH. This is the power beyond function/port on your joystick valve. What happens on my valve is there is also a plug that has to be installed inside the valve to route the fluid to the 3PH instead of back to the sump. If that plug gets loose, similar sypmtoms appear to what you've described. My guess is that you valve has something similar, although I'm just not sure if your valve looks anything like mine. I would guess this because you have to have a backpressure situation before fluid flows to the 3PH. That's why it won't work until you curl your bucket all the way up.

Anyhow, on my valve there is a hex head cover that has to be removed and the plug is below that. It takes an allen wrench to tighten the plug. I've included a picture of my valve and the cover's location, but I have no way of knowing if your valve looks or works anything like mine. It does seem strange that you would have this happen at the same time as the hose leaking. Coincidence? I'm just not sure.

 

[magicheater]

Sounds to me like you have the roll up action in series with the 3PH somehow.
Recheck your connections, if it worked before you did the hose work, chances are that it is something you did. I always go to the last thing done when troubleshooting a problem. Maybe a piece of dirt got in there.

 

[trudie1]

I place the 3 PT lever in the raise position and nothing happens at all, as soon as I roll the FEL up the 3 pt raises. No other FEL operatons have any affect on the 3pt raising. Holding against the relief will not lift the 3 pt and no other actions of the FEL will cause the lift either (dumping, lifting etc.) Thanks

 

[trudie1]

Thanks I am going to the barn to have a look.

 

[trudie1]

Yep thanks, and I totally agree, I even reversed the hoses to see if somehow I crossed them up during the install but no luck. Thanks

 

[trudie1]

1. Does the 3 PH work when curling the bucket (FEL valve activated)? Yes but only when curling
2. Does the 3 PH work after bucket is curled and is held against the relief? No only when actively curling
3. Does it have to be curl, or does it work the same when dumping, too? Only when curling

 

[DiskDoctr]

I place the 3 PT lever in the raise position and nothing happens at all, as soon as I roll the FEL up the 3 pt raises. No other FEL operatons have any affect on the 3pt raising. Holding against the relief will not lift the 3 pt and no other actions of the FEL will cause the lift either (dumping, lifting etc.) Thanks

Odd. ONLY the curl, not the dump? Sounds like a blocked port/valve/spool.

The hydraulics experts will surely weigh in, but here's what I'm picturing.

Your fluid go into IN on FEL valve, passes through all the OPEN CENTER (OC) spools to the TANK return (OUT or T) and to the POWER BEYOND (PB) port to power the 3 PH.

If the OC portion was blocked in the curl/dump valve (dirt, misaligned, whatever), then the fluid would be blocked from going to the PB. When you work the curl of the bucket, fluid flows through the opening created by the new position of this spool.

The fluid then goes through the rest of the valve (OC) and to the PB and the 3PH just fine.

Since it won't work when finished curling and held against the relief, I'm thinking it is possible the curl spool's/valve's OC is actually blocked and the only fluid you are getting to the PB and 3 PH is from the return side of your curl cylinder. That would explain why it doesn't also work when dumping with the same spool.

Of course, only a part of the spool could be blocked on that valve, which would explain it, too.

Are you comfortable pulling that spool out? Could be dirt, could be bad oring, etc.

How long did it sit with an open system (hoses off or ports exposed to air/moisture)? Maybe some rust or debris got in there...

Do you have a pic of the valve?

- JC

 

[magicheater]

Did you use teflon tape by chance, or was there some on there before? I have had an instance of a piece getting into a system.

 

[J_J]

I am surprised that you have not put a gage in the system. When you operate the 3pt, you are using the pump fluid out of the PB fitting. If you put a gage in the input to the valve, I think you will locate the problem. If everything is working normally, when using the FEL, there is no fluid to use for the 3pt. Did you do what Jinman said about the PB plug and hex screw?

All fluid from cylinders go to tank port.

Any relief fluid goes to tank.

If you are only using half of the fluid for the cylinders, then the other half should be flowing out the PB fitting to the 3pt.

I would attempt to take the valve apart and clean it.

 

[trudie1]

No tape at all but a good thought, I am going to attempt disassembly to check for debris etc., Thanks

 

[trudie1]

System was only open for about a day,but I am going to try the disassembly route and check for any dirt etc. Thanks

 

[trudie1]

Yep thanks, I am going to try the disassembly/cleaning route first and see if anything shows up. Thanks for the input.