Cub 2072 Lift Cylinder only goes one way, assume the control valve is stuck, any suggestions on freeing that up?

[fredgeorge]

Hello
I've owned this tractor for a while and it has always been a reliable item. It stopped running, and then sat outside for several years (I know bad).. and when I decided to get it going again the lift control levers were struck, and would not move. Some PB blaster and pressure worked and both of the levers now move easily.
However, pushing the lever to lower the mower deck (move the lift cylinder ) does nothing, , then over time the weight of the deck will cause it to go down partially, but then when you move the levers that divert the hydraulic fluid it will only raise the deck to full up, and never move the cylinder to lower the deck.
It goes forward and backward just fine, has power steering that works fine, and was low on the Hytran fluid , so I added some, and all the other hydraulic features work well, the control valve just refuses to divert the fluild to the top and bottom of the lift cylinder.

I haven't tried opening up the hydraulic hoses, to see what kind of fluid flow happens, and removing the lift cylinder doesn't look like an easy job.

Anyone here , have suggestions on what to try, I would greatly appreciate it. Hope someone has a good idea.

At I am pretty sure the lift cylinder is not stuck, because when it drops the deck down of it's own accord, pulling the lever bangs it full up in a big hurry, it just won't go in the opposite direction.

Thanks again for any ideas from the experts here

 

[fredgeorge]

Ok.. Decided to carefully inspect the lift control levers. It became obvious that the lever that was not operating correctly had some surface rust at the very top exposed portion of the cylinder that slides in and out of the lift control valve body. The adjacent cylinder was much cleaner and penetrated deeper, on further inspection it was clear that the direction that was obstructed was the direction the lever needed to go to allow the lift cylinder to raise the mower deck. Two screws to remove the plastic gas tank, some emery cloth to remove the surface rust, and the cylinder then operated as needed, and the lift cylinder now goes up and down as needed, and I have a tractor much closer to be ready to sell, as it operates as designed. Glad I found the issue, perhaps this thread will help someone else in future.
Regards all

 

[cubs4lifeofme]

Great job on finding and fixing the problem.

 

[MikeBrindle]

I actually found an easier way to deal with a similar problem on my 782. I just filed a slight dash in the side of the control lever where it was contacting the instrument panel at the maximum end of its motion. This gave the lever an extra 1/2"or so of play which was all that was needed to allow the deck to move properly. Sometimes lazy is best.

 

[cubs4lifeofme]

I love lazy fixes. lol

 

[Todd]

Glad you found it. Now I won't have to go into how I just assumed you were in a gravity-cavity.

 

[mgonitzke]

I actually found an easier way to deal with a similar problem on my 782. I just filed a slight dash in the side of the control lever where it was contacting the instrument panel at the maximum end of its motion. This gave the lever an extra 1/2"or so of play which was all that was needed to allow the deck to move properly. Sometimes lazy is best.

Fix it right or you'll keep doing it over and over.

The control valve mounting plate probably wasn't quite tight enough on the steering column and slid down a bit. All you have to do is loosen the 4 nuts on the U-bolts, slide it back up, and re-tighten them.

 

[MikeBrindle]

I had already adjusted the mounting plate on the steering column as far as possible and it didn't help. I do agree the original problem was probably as described above (corroded shaft), but I found by filing a small slot in the back of the lever so I got a little more lever reach, I haven't had any issue in the last 2 years of operation. So, I guess it wasn't a "bad" fix, even if it wasn't the "right" fix. And it was definately only a 5 minute job. As my gramps used to say, time is money.