Kubota L3400HST 3-Point Lift Issues

[BLane3400]

Good Morning,

I have a L3400HST, 170 hrs, that is giving me some trouble...the FEL is working great, but the 3-Point lift only raises under high RMP's. If I bump the FEL control at low RPM the 3-point lift will come up a little each time. I have changed the filter, and fluid (8 gallons). I'm not sure when this problem started because I've only had the tractor running for a couple days...I purchased the tractor, and had to rebuild the engine, and thats a whole other story!

Has anyone had this problem before? Any ideas are welcome! Thank you,

 

[teg]

Might be a crack in the hydraulic return hose (down by your right foot), common problem, lets air into the system. But... Need to hear about the engine rebuild... user error or what happen?

 

[BLane3400]

I traded a 2007 Yamaha 350 2X4 for a 2008 L3400HST 4X4 & FEL...the engine was completly apart due to operator error; they now know that tractors aren't mad to play in mud & water! I make the trade, and start ordering parts...I wish Kubota parts prices came with better service! I ordered the upper & lower seal kit $300.00, crank shaft $1,500.00, piston rings etc. Please note that the seal kits have everything, but the head gasket...nobody at kubota thought I should know this until after I started putting the engine back together! So I get all the parts in and get everything together...try to start the motor, and the exhaust is blowing out of the intake & I get worried. I call the local service department that I spent $4,000.00 at a few days ago, and was informed that the timing was off. I took everything off & found 2 bent pushrods. I get the timing set again and after the rods arrived got everything back together; turned the engine over and same thing happened...along with 2 bent rods. I call Kubota, and they didn't have an answer...I called a local tractor guy and explained the issue, and he told me that Kubota engine valves should be adjusted different than others tractor engines...after the 2nd set of rods came in & valves were adjusted properly it ran like a top!

If I had to do this over again I would purchase the new engine for $5,200.00!

 

[BLane3400]

Thanks teg, but I didn't find a crack in any of the 3 hoses...the crack would leak wouldn't it? Any other ideas?

 

[teg]

It didn't leak on mine (no pressure... if anything it's sucking air in). Since power steering is fine (?), and FEL is fine. There's a valve under and in front of the seat that controls the drop rate... might open that to see if it helps. Something easy at least to check...

 

[HydroTek]

Check your three loader valve lines for proper placement, sounds like you have the inlet and power beyond lines swapped.
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Inlet hooks to the pump, power beyond to the tractor lift, return ..well, to the return
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[BLane3400]

I change the lines around yesterday...the FEL still worked, but the 3-point wouldn't do anything at all. I'm going to replace the return line in the morning, and see what happens.
Thank you for all of your help...hopefully this will work!

 

[teg]

Let us know what you find out... have you check the pressure of the system? try cycling the system a few times... can the 3ph raise up with weight on it?

 

[BLane3400]

I'm clueless about pressure testing the system...I may leave that up to the pro's!

The lift will raise about half way with a load on it at high rpm's, or by bumping the FEL control several times.

 

[teg]

I'm very surprised that other owners of L2800/L3400 have not "picked up" on this thread. Wonder if it should have been in the kubota section

So the machine was abused... in mud and water... The thing that is weird is that the 3ph uses the same hydraulic fluid after it goes though your FEL. Will the 3ph stay up with a load?

 

[r8nger]

Sounds like the oil is bypassing in the 3 pt lift cylinder Maybee ?pressure spike from the front loader giving it enough to lift?

 

[Chilly807]

Other than possibly mis-placed hydraulic hoses, it sounds like there may be more issues than just the engine. If I get a chance tonight I'll take some pictures of the hose routing on mine from the loader to the 3 ph so you can compare that to yours.

It might be the return hose from the loader plumbed into the inlet of the 3 ph, which would give the 3 ph a shot of oil every time the loader moved. The fact that it works better at high rpm and not at idle is odd, if the cylinder was messed up it shouldn't hold it's position after the rpm came back down.

It might be worth your while to take a close look at the linkage from the position control lever to the 3 ph valve, as well as the feedback linkage from the lift arms to the valve.

Sean

 

[BLane3400]

It wasn't really abused...just a dumb mistake on hour 160! I've tried everything & it is now above my level...it's on the way to Kubota shop.

Thank you for all of the ideas...I'll let you know what they find.

 

[HydroTek]

Try disconnecting the loader valve hoses at the couplers, like you were taking the loader off the tractor. When you do this, you will hook the pump hose to the lift hose to complete the circuit. The return hose is left un-connected. Will the lift work now? This will eliminate any problems in the loader valve.

Trace the hoses to their locations if your unsure which hose is which.
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[BLane3400]

The local shop is going to call when they get a spot open...so I'm still playing with the tractor. I used the FEL this afternoon for about 15 minutes, got off to double check for leaks, and noticed the lines were hot. Not sure if this is normal...I'd say they were 110-130 degrees. Is that bad?

 

[HydroTek]

Nope, not unless it is hot where you are Likely the hydraulics are "on pressure" ..your Kubota should idle smoothly with no hissing in the valve or pump area. Pop those hoses off like I posted earlier, and connect the pump and lift together, I think it shows you how in the owners manual.

Another check is to "feel" the hoses with the engine off, then do it again with it running. Should not be any "tight" hoses.
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[BLane3400]

I didn't get a manual, but it's on my todo list tomorrow...I'll give it a try!

Thanks!

 

[Chilly807]

The attached pictures show where the connections should be for the loader and 3 point hitch. The three hoses shown terminate at the connection plate under the right side floorboard, and at the loader valve. The fourth hose (remote return) in the first picture is tee-d into the return line loader valve, and isn't a factor.

I have a rear remote connected between the loader valve and the 3 point, so the outlet from the power beyond on my loader valve goes to the inlet of the remote valve. Yours should go to the 3 point connection as shown in the pics.

Sean

 

[Chilly807]

In these pics the green arrows indicate fluid flow direction.

It might be worth checking the system pressure, at idle it should be no more than a couple hundred psi, if that, as long as nothing is being operated hydraulically. If it's going over the relief valve all the time it'll be about 2200 psi.

Sean

 

[HydroTek]

Great pics Chilly807 just what was needed here :thumbsup: ...BLane3400 do you see the top two hoses in the pic with the silver block? The loader will work with those hoses swapped, but your 3pt lift will act like you have been saying.

When you take this loader off, does the loader valve stay with the tractor? I think from looking at the pictures, that I assumed that the valve stayed with the loader. I apologize if I confused you. :ashamed:
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