Hydraulic cylinder rebuild

[seahaul]

I have a LoBoy 154 with 3-pt hitch that leaks down. Trying to rebuild the cylinder but cannot figure out how to remove the end cap in order to get to the o-rings inside. The end looks like just a seal without any holes to insert a tool to unscrew it. There is nothing on the outside that holds the cap in place.
Has anyone taken this cylinder apart and can tell me how to remove the end cap?

[Bob McCarty]

I haven't worked on one before, but here's a page from the parts manual: http://www.cleancomputes.com/Cub/Number ... e%2009.jpg
It looks like you might be able to just pull it apart (?).

Bob

[Eugene]

Is the cylinder leaking hydraulic fluid to the outside/external? If there is no external hydraulic fluid leak, the diverter valve is the probable source of the leak down.

[seahaul]

No fluid is leaking to the outside. Wasn't sure whether the problem was with the cylinder or diverter so I thought I'd fix both just to be sure. I'll do the diverter first and see if that fixes the problem.
Thanks for your help. The parts diagram helps greatly too.
Charlie

[gitractorman]

What do you mean about the hydraulics leaking down? If you mean that the hitch eventually lowers to the ground when you've parked the tractor overnight, that's common. When they engine is shut down the hydraulics release and allow everything to drop. There's nothing you can do to fix it.

Now, if while the engine is running, the hitch gradually drops, then you have a leak in the system somewhere, and it would almost have to be a leak to the open, not internally, meaning you should have hydraulic fluid loss and laying somewhere. There isn't anywhere for the system to lose pressure without the system losing oil. Meaning, you would have to top off the hydraulic oil all the time. If this isn't the case, then I'd say you don't have a problem.

[Eugene]

If you mean that the hitch eventually lowers to the ground when you've parked the tractor overnight, that's common. When they engine is shut down the hydraulics release and allow everything to drop.

The hydraulic system on my 154 does not leak down when the engine is shut off.

I don't know how your hydraulic system in plumbed. My 154 has two diverter valves.

One other location of check for the hydraulic leak down is the control valve.

Edit: The service manual has diagrams of some of the different hydraulic systems installed on numbered Cub Low-Boys.

[seahaul]

My 3-pt will "leak down" while the engine is running, but there is no loss of fluid to the outside anywhere. I suppose there can be one (or more) causes: lift cylinder, control valve (mounted under the gas tank to lift up/down), or the selector valve (mounted on the tunnel cover,to choose use of 3-pt or belly mower lift).
This appears to be a pretty common problem as I have three LoBoys and they all do this. One of these does not have the selector valve (mounted on the tunnel cover) so I've ruled out that possibility, at least for that tractor.
Since I still have not found a way to take the lift cylinder apart, I will concentrate on rebuilding the control valve for now. Will let you know what works.
Charlie

[seahaul]

I found the answer to my original question, "how to take the cylinder apart?" After disconnecting the hydraulic hose, you can look through the hole and see the end of the piston rod. It has a "stop pin" inserted through the rod that prevents the rod from being pushed all the way out of the cylinder. With a magnet, I was able to remove that stop pin and then the rod pulled right out.
There is a rubber o-ring (wiper?) on the piston rod that can be replaced. Hopefully this will stop the 3-pt from leaking down.
Charlie

[BigBill]

If your not seeing any oil leaking on the outside then there is a leak down within the system.

You have a selector or diverter valve that selects the rear 3pt hitch or the center lift for the mower. The selector valve could be leaking down. It takes 9/16” square o rings. My int154 #1 has the same problem.

[tmays]

I have the same problem, but no 3 point. Just a belly mower. Leaks down rather quickly while running. Curious to know what the problem was when you find it

[Eugene]

If your not seeing any oil leaking on the outside then there is a leak down within the system.

You have a selector or diverter valve that selects the rear 3pt hitch or the center lift for the mower. The selector valve could be leaking down. It takes 9/16” square o rings.

Selector valve if your tractor has no diverter valve.

[jlogan]

Did anyone figure out the problem? I’m having the same problem and don’t know where to start. I don’t have a valve to select between the mower deck and 3 point. I’m not losing any fluid but the system isn’t holding pressure and the deck and 3 point drop down pretty quickly.

[Ronnie]

I messed with my cylinders which are also drifting down for hours and after hours of research I finally found how to take them apart. The end “cap” does NOT come off. To get the cylinder rod out you have to look into the bottom valve where you would attach the hose. Rotate the rod within the cylinder until you see a metal pin. Line up this pin and the valve hole and the pin will literally fall out of the cylinder allowing you to completely remove the rod. To put the pin back in just line up the holes again and drop it in! It’s that easy. Good luck

[seahaul]

response to jlogan:
My problem turned out to be the selector valve. It needed new o-rings installed.
Charlie