Hydraulics / lift question

[rinms]

I am new to this forum, and this is my first post, so if I inadvertently violate any forum protocols, I apologize in advance - I'll learn.

That said, here's my situation:

I have been asked to help "sort out" a Yanmar / Zen Noh 1700. It belongs to a friend whose father passed on and we cannot find any manuals, etc. in his papers. I realize those would be helpful, and we intend to order them, but I'd prefer to get the little guy "up and running" and then make one order for everything it will need, manual included. In the meantime, I've searched the forums as well as the 'net, and I've hit one problem. It is in what appears to be good overall condition and appears to have had both careful use and maintenance. However, it has sat unused for about 1-2 years.

I've managed to get it running and it seems to run properly. Before we attempted to start it, the 3 point lift lifted easily and would not stay up (we had to tie it up to load it on a trailer). Once running, the arms lifted and will not move with what seems to be to lift control (a lever on the right side fender area that impinges on what appears to be a hydraulic valve under the seat). Moving this lever up or down does not seem to do anything, however this lever does impinge on the "button"/rod on what appears to be the valve. But since I'm not entirely sure of the operator controls, I cannot yet attempt to determine if the system is working and I'm not operating it correctly, or, if I am operating it correctly, if there is a problem. Can anyone give me a general description of the hydraulic controls?

As I learn, I will "pass it on," and be happy to give back to the forum, but for now, I am a 1700 newbie.

Thanks in advance.

 

[winston1]

Not familiar with the 1700 but if you look at the attached drawing part #14 is a roll pin that goes through part #19. Not sure which position this lever is to be in but experiment. I don't think you will harm anything. Many Yanmars have a stop valve located about middle ways under the front of the seat. If this valve is closed or nearly closed your three point won't go down. Open this valve if there. Try these items, if they don't help we will go from there. Yanmar Tractor Parts: THREE_POINT_CONTROL

 

[rinms]

Thanks for the fast reply and the link. This does look like the controls on the tractor in question - I cannot say if it is the _exact_ same as I haven't taken anything apart. The lever labeled "50" is what I thought was the control lever for the lift. Is this correct? On the tractor in question, what appears to the the bar, 34, on the rod, 27, depresses and "releases" the valve pin, 17 (sorry if the terms I'm using aren't correct, but there is no part names on the diagram in the link). However, even though the lever, etc. appear to operating correctly and as designed, nothing happens when the lever, 50, is moved - the lift remains in the up position and cannot be lowered, even by downward force (a pretty large, strong guy pushing down on the arms). Also, if you know, what does the "sub-lever," labeled 11-58 do? It moves in a semi-circular slot and appears to have two notches/locking positions at either end of this slot.

Thanks, again.

RinMS

 

[rinms]

Oops, hit send too early. I have adjusted the knob labeled "Open" and "Close" with directional arrows (facing toward the front of the tractor, under the seat, accessible while seated in the seat) and its position seems to have no affect on things. I assumed it was some type of "valve lock" that would prevent the release of hydraulic pressure (for example, to secure the arms up), and I did try to experiment with its position, but ??? I also tried the lever (what appears to be 11-58 in the linked drawing) in both of its "notch" positions. Saw no noticeable affect in either position. It seems from the drawing that this overall assembly is simply a horizontal hydraulic valve, so perhaps it has gummed up from its long lay-up? Before I start attempting to tinker with it, does anyone have any potential pitfalls or tips specific to this unit or is pretty straightforward?

Thanks in advance.

 

[normde2001]

If you lifted the upper arms fully up by hand it's possible you unseated the lift piston from it's cylinder and will have to dis-assemble to restore.

 

[mark777]

If you lifted the upper arms fully up by hand it's possible you unseated the lift piston from it's cylinder and will have to dis-assemble to restore.

That was the very first thing that came to mind, Norm.

Over extending the rock shaft arms ever so slightly does pull the barrel out of the hydraulic bore. Which, in turn, keeps the mechanical assembly stuck in the upright position.

 

[winston1]

Did you look for a stop valve under the seat?? Here is a drawing of the piston Norm referenced. You can view some ref# by clicking on them. http://www.hoyetractor.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=HTE&Category_Code=YM17003PT

 

[rinms]

Norm, Mark, and Winston -

Thanks for the ideas and the link. I suspect y'all may have hit the piston on the head. When we loaded the little guy up, we had to lift the arms to get it on the trailer. I attempted to only lift them as far as needed, but that may have been a wee bit TOO far - any idea as to how much manual lift will unseat the piston? I'm gonna take a look at this today and will post results ASAP.

Also I notice that some of the posters here are also posters in the Yanmar forums, er, elsewhere, and I had intended to post/update both so as to "expand the knowledgebase." OTOH, if the same folks read both, is there any reason to do so? Also, I'll be glad to post any and all numbers markings found and/or email them to Mark for that list (it appears that Mark maintains it???).

Thanks,

rinms

 

[deepNdirt]

Hello rinms and welcome to the tractor world :thumbsup:
I have experienced issue's with the lift on my 1700 as well, and while not being a pro on tractors I have managed to learn as i go and with the help of the great members of TBN I have accomplished a few repairs on my own,
not that this will help any! but here is a link to back when I had 3 point lift propblems, http://www.tractorbynet.com/forums/hydraulics/167768-rear-lift-wont-drop.html
You may find something that can help you, if you do need some help with the breakdown of the assembly ( how too? ) I've been there done that 3 times so far
good luck

 

[California]

I think your YM1700 is identical to YM2000 (except smaller displacement engine) and their US versions YM195 and YM240, so searching on any of those terms here might find what you want. Also, all the YM240/YM195 manuals are available if you need full documentation.

Before you tear anything apart - The knob under the front of the seat (Servicing Valve) has to be Open for the 3-point to lower. And there is another small valve under the left side of the seat (Drop Rate Valve) that also has to be open. That one is hard to find - it is a rollpin driven through a small shaft to make a handle.

Try opening both those valves, before dis-assembling anything.