Help! Three point

[Dalton]

Hello to all,
Having a problem with my three point. Machine is a Kubota L-345 W/ FEL. Problem is three point will not lift, neeed to run RPM's up to 1000 to get slow lift. After lift is up I let off RPM's and it drops right back down! Have already cleaned hydro filter and put fresh fluid in. Strange thing is that FEL works just fine. Should also mention that recently aqquired backhoe hitched up and operated fine, independent hydro pump on back hoe so no additonal usage of tractors hydro system. After unhitching backhoe and hooking post holer drilled ten holes and on eleventh hole lift arms would not lift. Any ideas on things that I can check out?

 

[DocHeb]

Any hydraulic valves stuck slightly open (i.e. not returned completely to the center neutral detent position)? I don't have Kubota experience, but something similiar happened with my TC40D that has three rear remotes. While mowing I tried to raise the three point - no response. Topped off the fluid - no response. I had bumped one of the rear remote control levers out of neutral and the hydraulic pump just popped the pressure relief and my hydraulic pump's entire output was being cycled through the unused rear remote system. Pushed the lever back to neutral and my three-point was miraculously restored.

 

[BillG_in_TX]

Re: Help! Three point problem L345

I had a similar problem with my L345 3pt last year. While it cured itself, "kubmech" had some good advice. Here's the thread.

By the way, if "rbargeron" doesn't see this post and respond, you might try sending him a PM (Private Message) at this page. Dick is a former L345 owner and knows the tractor inside and out.

 

[jinman]

Dalton, your problem sounds like a broken internal seal or gasket that is letting the fluid flow to the return side or leak inside the hydraulic case and back to the reservoir. Normally, when a control valve is stuck, you will get no movement of the 3PH. Consider this: If your hydraulic lift cylinder was leaking, you could get enough flow by increasing the engine rpm so that your 3PH would lift. As soon as the engine slows and the flow decreases, the 3PH will drop because the cylinder is leaking faster than you are pumping. It doesn't have to be the main cylinder to cause this, it could be a leak somewhere in the plumbing you added for your backhoe. It just sounds like a leaking seal to me rather than a stuck control valve.

Now, having said that, if a pressure relief valve was stuck open, it would act exactly like these symptoms too.

 

[Dalton]

Thanks to all replies. But no luck yet. I have looked at the valve body(?) and there is nothing that I can see that could have been bumped or knocked out of adjustment.
When looking at the tractor from the rear, the valve body is on your left under the seat. It has two hoses that feed in to the loader control. I don't see anything on it that could be adjusted to regulate flow. Am I missing something here?
On the right side the lever that actuates the lift arms goes directly into the housing.
The back hoe has an independent pump that slips onto the pto shaft. So there is no plumbing for it at all. What I am wondering is that the weight of the hoe may have weakned some seal in there.
Is there any way to test or futher narrow down what the problem may be? I really do not want to have to have a shop fix this for me and hate to even ask what the repair might cost. Any ideas though on what shop cost may be?

 

[rbargeron]

Hi Ray

Couple questions - what position is your draft control lever in? Is the draft-sensing rod in place and functional?

The little aluminum block under the left side of the seat is the fitting that allows a connection into the tractor's internal hydraulics. There was a blue cap there originally that routed the oil from one hole back thu the other - the aluminum block replaces the cap and isolates the holes so you can connect supply and return hoses. You're right -there's nothing to adjust.

For what it's worth, my guess is the FEL control valve is letting some oil bleed from pressure to drain ports. It doesn't really sound like a low-oil-level problem. The arms would tend to move up in little jerks, and would not bleed back down. Sounds more like an open flow path somewhere.

On L345 loaders running on the internal hydraulics, if the loader valve is in "float" the 3-point hitch acts like you describe. If there is a load on the 3-pt arms, the loader would start going up if the 3-pt lever was raised. (pressures would be balanced but the big end of the cylinder would develop more force).

Sounds like something is bleeding the high-pressure side of the circuit or the 3-pt ram plumbing (inside). But, like all such problems, double-check all the easy stuff before diving deep.

Does your loader function normally? Full range with a load?

The problem could be small (or possibly not). Unfortunately my L345 manuals went with the tractor - so I'm not as much help as I'd like to be. I'll see if I can dig up some more info.
Dick B

 

[Dalton]

Hi,
Sorry it took me so long to respond, a thousand things to do and never enough time. Anyway I got out there today and took the quick connects for the loader off from the loader valve body. Then just connected them together, eliminating the loader from the hydro system. Started up the tractor and the lift arms came right up at a low rpm idle. Shut the machine down and the lift arms dropped right back down.
One other thing that I thought of was that when I hooked the new back hoe up I connected the lift arms and then used the hoes out riggers to line up the top link hook up. This lifted the arms up from their down position. I noticed that after the hoe was hooked up the lift arms would not go all the way down. Don't know if this had anything to do with current problem. Any suggestions are greatfully appericated!