Yanmar 1500 stuck lift arms HELP!

[David R]

I just bought a YM1500. The lift arms are stuck in the UP position.

I have removed the dial nob below the seat, and the thing that it depresses when it is opened and closed does not seem to move.

The fluid is milky - water, but the internal parts seem to be in good shape. No rust, etc.

I was told to remove the CYLINDER HEAD - but after removing the four bolts that hold it on - it is still on... I semi-gently taped it with a hammer - but given the cost of this part, I decided to post here first...

No luck removing the cylender head.

Questions:

What do I do next?
Such thing as simply flushing the fluid, and that will fix it?
(BTW, I can stand on the arms and not move them.) 248#

I am reluctant to keep taking things apart, BC I feel I am at the point where i have found something that seems NOT to be working (the problem)

That SEEMS to be that the piece the dial under the seat pushed is not really willing to move.

Any comments are welcome.
Thanks.

 

[David R]

Lift arm CYLINDER head assembly is now removed from tractor.

the problem is clearly inside of the piston head assembly.

The problem now is removing the CYLINDER head from the housing. All of the parts have been very tight coming apart.

Any tips on pulling the hydraulic cylinder apart would be great

 

[David R]

well, the lift is taken apart - and here is the final problem.

Water was allowed into the hydo fluid - hence the creamyness.

Over time, and a lack of use of the lift arms, the oil settled.

leaving the water...

which rusted...

and now keeps the parts arms from moving.


What is the best way to deal with this?

continue to take apart, or buy a replacement?

 

[mark777]

I would continue with the disassembly.

Remove all the parts and clean with appropriate solvent after using a bench grinder style wire wheel. I would also clean the cylinder bore with soft Scotch-Brite or medium steel wool attached to a small wooden dowel. Blow out (compressed air) or flush out assembly (carb spray) replace the 'O' rings and assemble with fresh coating of appropriate trans-hydraluilc fluid JD303 or higher rated fluid.

Physically test the assembly (on the bench/table) and completely drain the hydraulic reservoir on your tractor. Remove the internal filter screen and clean it with gasoline or fresh diesel and finally a good carb spray, let dry and install and add your new hydraulic fluid...then install your repaired rock shaft assembly.

I would also check the square block on the 3PH sensor rod to be sure the shaft travel is not allowing the arms to over extend.

Good luck!

 

[David R]

I am at a bit of a stalemate in the disasembly - I cannot revove the lift arms from the housing.

the plate on the left is removed, and both bolts are removed.

Any suggestions?

(I am going to get some solvent this morning to let it soak)

Once this is done, where/how do you put presure on these arms to pull them off?

Thanks in advance.

 

[mark777]

Now I'm confused !

You shouldn't need to remove the arms to access the hydraulic plunger....

You do have the entire rock shaft assembly removed from the tractor right??

What I mean to say is you have a great big opening in the rear of your tractor and can see the PTO gears..etc?

 

[David R]

Now I'm confused !

You shouldn't need to remove the arms to access the hydraulic plunger....

-you are right, but at the time, I was not sure if the arms were the problem, and I thought that they would need to be removed to remove the plunger.

You do have the entire rock shaft assembly removed from the tractor right??

What I mean to say is you have a great big opening in the rear of your tractor and can see the PTO gears..etc?

-you are right, but at the time, I was not sure if the arms were the problem, and I thought that they would need to be removed to remove the plunger.
IT IS ALLLLLLLL Apart!
See next post.

 

[David R]

Posted for the sake of others with this similar problem.

For what it is worth- this was the problem...

Primary problem:

The tractor was stored (extended storage) with the lift arms in the UP position.
this left the hydralic cylinder filled with fluid. In order for the arms to drop, the fluid must be pressed out of this cylinder. (the pump pushes fluid into the cylinder to push the lift arms up - weight simply pulls them down.)

So someone lifted the arms all the way up w/o an implement on it.
The cylinder head got stuck in this up position. A little rust, a lot of presure from the cylinder full of fluid...)

Since thier is no real way to push it back down, the housing was taken to a machine shop. I had them put it in a vertical hydralic press. and push the cylender head back into the housing. We simply pushed on part that engages the splined shaft that lifts the arms.

It worked with almost no resitance whatsoever.

Now the arms can be moved up and down.


Secondary problems: Many of the parts had not been used, and were not really working right. I took all of the parts that mount to the housing off and took them apart, and changed the o-rings, and lubed them up real good.

Lots o' fun.... when things are working out good!

 

[BruceR]

Welcome David,
Looks like you have the makings of a first class Yanmar owner.

Bruce