3-Point Hitch Kubota M4900 3PH lift arms cycling up and down

[TRM 1]

The remote valve actually bolts to the side of the housing and is fed from the housing itself. So it really doesn't have any hoses feeding it. It has ports (I assume) that feed the valve. We also have a M4030 with a Bush Hog loader on it that is fed from the remote valve and when you want to use the loader you lock the remote valve in position to feed fluid through the remote to the front end loader. When the valve is locked in place like that the 3 point hitch doesn't work although it does stay up and doesn't drop. When you want to use the 3 point hitch on that tractor you put the remote valve in the neutral position and the lift works then. So I would think the m4900 would be the same as far as using one or the other at a time although the lift shouldn't drop down when you use the remote valve.

 

[ArtMech]

Don't know how much M49 differs from my M90, but the Troubleshooting of Service Manual describes a symptom as Implement Hunts (Moves Up and Down). Could it be the same according to your description - lift arms cycling up and down?

If yes, the probable causes and solutions are:
Poppet valve, poppet seat surface damaged............replace
Check valve, check valve seat surface damaged......replace
Control valve O-ring worn or damaged...................replace

In case if above info is useful, I can take a look at the repair technology.

 

[TRM 1]

Well the arms only move when you operate the remote valve and take away the pressure from the three point hitch. the arms only move down so far when you operate the remote valve and once you release the valve the arms return back to the original position. Maybe I can get time to fool with it tomorrow. Thanks to everyone for the help!

 

[MHarryE]

Sometimes my brother-in-law has me drive tractor when he gets real busy. The first time I went there I noticed the 3 point arms were down but the lever was full up. I asked about it and he said the problem is dairy farming sucks so he can't afford to upgrade tractors. As they age, the control valves leak more and more and by the time you get 8,000 or 10,000 hours on them they will leak. They stay up when running although they will cycle every now and then so he doesn't see a need for his overworked mechanic/driver/all around good guy to overhaul. Sounds like a leaky valve is your problem. I noticed my L5740 with only 150 hours cycled the lift arms up a half inch or so the other day when I was working on the ground and had the tractor idling. I need to watch it more to see if that was a one off or if something may be going wrong. What is okay for my B-I-L is not always pay for me.

 

[ArtMech]

When I was installing a remote valve myself, there was an extra valve internal piston kit in a box. Can't remember what for. Probably depending on the number of valves to be fitted, must be used either one kit, or another. The extra kit consists of a piston and spring, which are different from the original one already installed inside the valve. I didn't use a rem. valve yet (the implement with a hydro cylinder I'll have only this summer) so I can't tell how the lifting arms would behave on my tractor when the rem. valve is activated. Suppose, if something wrong, I'll have to replace that kit.
Maybe incorrect piston kit is installed inside your rem. valve? Do you have that issue from the moment of obtaining a tractor, or it happened later?
Or it could be broken piston or spring of a valve?
It's pretty easy to remove rem. valve and to inspect it on the M tractors.

 

[TRM 1]

The m4900 was having the issues when bought which was a couple weeks ago. we noticed the problem after we bought it from a private individual. The remote valve is located under you right leg under the floorboard and the control levers for the three point hitch. On the m9000 the valve is located on top the housing at the back of the tractor. It would be easy to work on the valves of a m9000 because of the location. The m9000 we have was bought new and we haven't had any problems with it of any kind.

 

[ArtMech]

OK, I didn't know M4900 has a different design of remote valve.
Whatever it is, I would blame the remote valve for the failure if you say 3PH operates perfectly since you're not touching a valve lever.

 

[Chilly807]

The problem with mine was that with the valve adjusted to the manual specs, it relied on continuing hydraulic flow to maintain the 3ph position. When that flow was interrupted, due to either engine shutdown or operating the loader or remote valves, the hitch would drop an inch or so. When the hydraulic demand was removed, the hitch would return to the higher position. Not a good situation.

This MIGHT be the problem with yours, if the valve set-up is similar to mine.

Sean

 

[bulldog69]

Sounds like a plumbing problem. If I remember right they make a kit for the loaders. It allows you to plumb the loader in without using the remotes. I don't think you will ever correct this problem unless you replumb the loader.

 

[TRM 1]

The loader I was speaking of is on a M4030su we have. The m4900 and the m9000 we have do not have loaders.