1700 Lift arms stuck in the up position

[BigMike915]

Guys, looking to see if I can get some pointers with a problem. My dad has a problem with his 3 pt. hitch, stuck in the up postition. He called me yesterday and said he was pulling some tree's with his tractor. He has the disc harrow attached and it will not go down. I am going to look into it this weekend and was curious as to what he could have done/broke to cause it to hang up. I figured with the weight of the harrow it would leak down, but he says it hasn't. He has not touced the valve under the seat so it should still be in the open position. Thanks in advance.

[284 International]

I would suggest verifying the valve is still open under the seat. Also check to make sure the position control lever is actually moving the valve position to allow fluid out.

I would also say be REALLY, REALLY careful!!! The implement is supposed to be on the ground, but isn't. Having a disc drop onto you or someone else would be bad news. I'd be really careful fiddling with the tractor, and make sure nobody is near where it will fall.

[BigMike915]

Yes, the first thing I'm going to do is remove the disc before proceeding with anything. Thanks for the suggestions.

[deepNdirt]

I have same tractor, and had same problem, using the same implement ( disc harrow ) what a coincident I had to remove the valve and install new O-rings inside, this will most likely correct your dads as well, Note: I'm not sure how to go about bleeding off the pressure before removing the valve, but be sure to have a way to rest the harrows on something like a set of jack stands, you can then remove the pins from both draw bars that attach upper and lower arms together, to safely remove the valve, I'll try and dig up the photo I have of the part that needs new O-rings,

[winston1]

Here is a good parts drawing of what you have. Yanmar Tractor Parts: HYDRAULIC_LIFT

[deepNdirt]

For now all I could find is the valve housing and the 4 bolts that need to be removed, along with the large Banjo bolt on top,
this is what you'll need to remove in order to get to the plunger inside that has the O-rings, I think I see in the illustration winston1 provided above the 2 O-rings I'm referring to, But while having it apart also be sure to inspect the smaller pc. inside the plunger/piston, there is a spring be careful not to loose this,
Oh! and I happen to think that if you let the tractor set a few hours or over night the lift may drop to the ground on its own, would certainly be much safer to work on with no risk of incident,

[BigMike915]

Thanks for all the help guys. I ran over tonight to take a look at it. First thing I did was remove the disc and pulled it in the shop. I noticed the valve under the seat was very tight, but it was in the open position. I took some big channel locks and turned it to the closed position then it free'd up enough to turn by hand. I turned it back to the open position, cranked the tractor and the lift is working correctly now. But now the valve is leaking hyd. oil every time I work the control lever. So I'm guessing I damaged something inside the ON/OFF control knob. Now when I get some more time this weekend I will pull it apart to see if perhaps there is a O ring or gasket in there that I damaged.

[deepNdirt]

BigMike915 , did you ever get around to removing the 3 pnt lift valve? I found the photo I had taken of when I took it apart, although the part the arrow is pointing to also comes out and this part can get stuck and needs to be polished up for smoother action,, In order to remove this part you have to locate and pull out 2 half ring looking clips, at first I thought this was one pc that had broken, But it is made this way I guess for easy assmbly/removal,
I could not find a breakdown image on this assembly so I hope the one I have here can help better to familiarize you with how it's suppose to go together,

[BigMike915]

deepNdirt, thanks for the reply and the pics. The control valve is working properly now. Only now the ON/OFF knob below the seat is leaking oil. I have not had the time to tear into it yet to see whats damaged and causing the leak. It getting close to time to prep the garden so I am gonna have to find the time soon to look into it. Everything is working properly other than the leak, though.