YM 135 3 point issue

[keenlanp]

Folks,
As spring approaches, it is time to start thinking about projects I have been putting off until it warmed up. My girlfriend owns an adorable little 135 she uses around her yard and for working on a prairie restoration (yes, she is a good woman and yes, I am a lucky man). Recently the 3 point won't lift what it used to and once it is up, if you put more weight on it, it will drop. The engine doesn't sound like the pump/3 point is maxed out, it just won't lift. Closing the valve under the seat has no impact on it going down. If the carryall is up and I step on the back edge, it will drop (again regardless of whether the valve is closed). After searching on this forum and a couple others, it sounds to me like this is a bad o ring. Does that sound right to folks? If so, how much of a project is it to fix it and will the bad o ring be apparent? Thanks as always for sharing the knowledge.

 

[bmaverick]

Folks,
As spring approaches, it is time to start thinking about projects I have been putting off until it warmed up. My girlfriend owns an adorable little 135 she uses around her yard and for working on a prairie restoration (yes, she is a good woman and yes, I am a lucky man). Recently the 3 point won't lift what it used to and once it is up, if you put more weight on it, it will drop. The engine doesn't sound like the pump/3 point is maxed out, it just won't lift. Closing the valve under the seat has no impact on it going down. If the carryall is up and I step on the back edge, it will drop (again regardless of whether the valve is closed). After searching on this forum and a couple others, it sounds to me like this is a bad o ring. Does that sound right to folks? If so, how much of a project is it to fix it and will the bad o ring be apparent? Thanks as always for sharing the knowledge.

Do you have the manuals? These would help greatly. If no, click on the link in my signature and find them for FREE at the Yanmar Tractor Owners Group.

It could be a seal or it could be the hydraulic filter needs to be cleaned or replaced. Maybe the fluid too.

Yanmar made our YM machines and the John Deere 50 & 55 Series machines together. So, the J20C fluid is spec'ed for our machines. Both Yanmar and John Deere worked on the Hy-Gard formula.

 

[winston1]

Attaching a thread from my old 2002D. Might help you some. yanmar 2002d hydraulic lift

 

[rScotty]

Folks,
As spring approaches, it is time to start thinking about projects I have been putting off until it warmed up. My girlfriend owns an adorable little 135 she uses around her yard and for working on a prairie restoration (yes, she is a good woman and yes, I am a lucky man). Recently the 3 point won't lift what it used to and once it is up, if you put more weight on it, it will drop. The engine doesn't sound like the pump/3 point is maxed out, it just won't lift. Closing the valve under the seat has no impact on it going down. If the carryall is up and I step on the back edge, it will drop (again regardless of whether the valve is closed). After searching on this forum and a couple others, it sounds to me like this is a bad o ring. Does that sound right to folks? If so, how much of a project is it to fix it and will the bad o ring be apparent? Thanks as always for sharing the knowledge.

The YM135 and the 155 (& 165) were the same tractor except for a slight change in the engine HP. My OEM Yanmar parts book covers both the YM135 and 155 in the same book and as far as I can see there are few differences. Certainly no differences in the hydraulic lift.

Those were really nice little tractors. Many were sold and yes, they are adorable. Hers is probably the lime green color. We still have our YM165 bought new and it is identical except for being red.

Anyway, what you describe is probably a worn o-ring on the lift cylinder piston. It is common for many tractors to use a rubber O ring there, and not unreasonable to need to replace it every 30 years or so. Replacing it is a simple & easy afternoon job if you have ever done it before- and not too much longer the first time. This is almost basic maintenance, therefore Yanmar made it easy to do without special tools - a good set of sockets and wrenches are about all.
Prepare by placing the lift arms in their lowest convenient position and putting a block of wood under them to prevent then from falling down any farther.

As I remember, there are two O rings that you need. One goes around the 3pt lift piston, and the other ring seals the cylinder to the head. Both are visible in this attached picture as parts 38 & 14. Might as well get #s 26 & 28 as well. And anything else you might think you need.
I like to use a sheet of the good 600 to 1000 grit wet-or-dry paper to shine up the inside of the cylinder in case of rough spots or some rust... not always necessary.

That's about it. I hope it sounds like a fun project. Design for simple upkeep is what these vintage Yanmars are all about.

 

[rScotty]

Folks,
As spring approaches, it is time to start thinking about projects I have been putting off until it warmed up. My girlfriend owns an adorable little 135 she uses around her yard and for working on a prairie restoration (yes, she is a good woman and yes, I am a lucky man). Recently the 3 point won't lift what it used to and once it is up, if you put more weight on it, it will drop. The engine doesn't sound like the pump/3 point is maxed out, it just won't lift. Closing the valve under the seat has no impact on it going down. If the carryall is up and I step on the back edge, it will drop (again regardless of whether the valve is closed). After searching on this forum and a couple others, it sounds to me like this is a bad o ring. Does that sound right to folks? If so, how much of a project is it to fix it and will the bad o ring be apparent? Thanks as always for sharing the knowledge.

If you PM me, I see that there is a .PDF of the YM135 service manual in my files.
rScotty

 

[bmaverick]

If you PM me, I see that there is a .PDF of the YM135 service manual in my files.
rScotty

Or just get it here.

Compliments of the Yanmar Tractor Owners Group on GroupsIO.

 

[rScotty]

Aren't those old Yanmars amazing! Here we have a brand of old tractors that are pushing 50 years old, that were never very numerous, and most of the ones looking for new owners already have more hours on them than most modern machines will ever see.

They are not even sophisticated mechanically. The older ones tend to be manual transmission, no power steering, low flow hydraulics, and lots only have the old transmission-driven PTO that was obsolete on US farms by 1950. The YM135/155 doesn't even have a water pump!

Yes, they cost less than new tractors, but they still sell for serious money. They aren't going cheap, and they are going to users; not collectors. Not yet.....

And in spite of the downsides, these old Yanmar tractors are so popular that there are more than a one Yanmar Club right here on the internet. The group here and the Yanmar Tractor Owners Group on GroupsIO are the two largest I know of, but I've been on several other groups through the years and am sure there are others as well.

 

[bmaverick]

And in spite of the downsides, these old Yanmar tractors are so popular that there are more than a one Yanmar Club right here on the internet. The group here and the Yanmar Tractor Owners Group on GroupsIO are the two largest I know of, but I've been on several other groups through the years and am sure there are others as well.

rScotty,

You are truly correct. And those painted JD green are still selling for top dollar too.

Over on the Russian/Ukraine fermer.ru website, there is a large following of Yanmar folks in the Japan compact tractor sub forum. They too prize the Yanmar, Mitsubishi, Iseki, Shibaura machines. Yanmar is considered the highest on the list.

Shibaura actually helped Yanmar with their first tractor ever. The A30. It was all Shibaura machine and Yanmar put their engine in it. This is in the 100 year history of Yanmar PDF document on the web.

Yanmar later teamed up with John Deere.

Shibaura teamed up with Ford, then New Holland.

Great history in the making.