3-Point Hitch 3-point Hydraulic cylinder has flow by

[clemsonfor]

Thanks for the two pics. Can you tell me why removal of the housing is necessary to make the repair ?

You have to remove the whole assembly so that you can rotate the rockshaft out of the cylinder bore and pull it out allowing you to take a a wood dowel or something and push the piston out that will be stuck in with friction from the oring in the cylinder. The rock shaft and piston ARE NOT connected!

Pulling the end cap off you have to pull something toward you that is inside a pipe of very similar diameter with a huge fat oring around the edges that creates friction.

 

[clemsonfor]

Here is my post.

http://www.tractorbynet.com/forums/yanmar/254837-clemsonfors-hydraulics-rebuild.html?highlight=

 

[Ben755]

Thanks to everyone for their input and comments on past experiences with this repair job. The posted pics are of great benefit also. I won't be going into this job blind now, and I'll know what to expect and can prepare somewhat for what I'll need to do when I start the job. I have about another week of pasture shredding to finish before I can get started on the repair work. The 3-point can still hold the shredder up, but as heat and pressure build, the lift arms start to fall slightly (about 1/4") and then jump back to correct itself . This occurs periodically, initially at about every 4 seconds, and later, every second, causing a slight jolting motion on the tractor.

 

[clemsonfor]

could be something in the valve worn too. Have you locked out the 3pt to isolate the cylinder to see if its the culprit and not the valve leaking?

The shaft on the valve can just wear in the bore and cause a leak. I replaced the orings in my valve as well but it still have a minor leakdown but I live with it. I rather it not but for the small amout it does and the cost of a new valve I will live with it.

 

[normde2001]

Sounds as if you need something like this. Have been using these check chains to determine the height of my cutter and keep strain off 3ph for about 15 years. Unfortunately don't remember where I got them or exact name.

 

[clemsonfor]

View attachment 485543Sounds as if you need something like this. Have been using these check chains to determine the height of my cutter and keep strain off 3ph for about 15 years. Unfortunately don't remember where I got them or exact name.

where do those attach too? looks like they go from the lower pin to the upper arms? how does that keep the pressure off the 3pt if they go to those?

 

[Gunny]

Check chains are run from the lower pin on the implement to the upper pin on the top link. Once adjusted, the implement is held by the chains, not the hydraulics. Another good thing with them is that if you have to lift the implement, then all you have to do is just drop the lift and it will go back down the limit of the chains, no need to adjust height up and down again.

Some people call them limiter chains.]

Here is a PDF on how to make your own

http://www.ntractorclub.com/howtos/pdfs/Limiter-Chains.pdf

Here is a set for sale

Chain Limiter Kit

 

[Ben755]

could be something in the valve worn too. Have you locked out the 3pt to isolate the cylinder to see if its the culprit and not the valve leaking?

The shaft on the valve can just wear in the bore and cause a leak. I replaced the orings in my valve as well but it still have a minor leakdown but I live with it. I rather it not but for the small amout it does and the cost of a new valve I will live with it.

The closed lockout valve under the seat will not hold the lift arms with load when the engine is shut off. I also notice some hydraulic fluid tends to leak under one of the end caps where the lift arm attaches to the shaft.

 

[Ben755]

Check chains ? Interesting idea - I may give it a try if I can put it together.

 

[normde2001]

Right, gunny, top link bracket. Chain Limiter Kit That would be the one.