hydraulic control valve stuck

[Grass Roots Farmer]

As posted a week ago my hydraulics stopped working with the lift arms in the up position. With help from this forum, I have drained the hydraulic fluid and today removed both inspection plates. I found the T- shaped control fork disconnected and successfully reconnected it to the jointed arms connected to the control lever. Moving the lever back and forth does not seem to release the valve. I am thinking I need to move the valve rearward to "open" it. Hand pressure does not seem to work either.

I don"t want to break the fork by using excessive force, but can I use a screwdriver (probably through the large drain hole) to pry the control valve open. Exactly where should I pry?

How far would the valve travel to be in the open position.

If I cannot move the valve, what is the next step?


Thanks in advance for getting me this far. Maybe I will get lucky and fix this darn thing.

 

[Jerry/MT]

I can"t tell you the exact distance that the control valve must move to open the exhaust port but it"s not much.

I would try prying on it through the drain hole if you can"t pull it backwards by hand. Try to limit the force you use however. You must have something caught in there if it doesn"t slide out with just a hand force applied to it.

If that doesn"t work, I think dropping the pump is the next step.

 

[Grass Roots Farmer]

Found the problem!!I jiggled/ pryed the control valve with a screwdriver through the drain hole and found that the little spring at the end of the control valve was broken and jammed in the exhaust port. A small piece of the spring came out and the remaining looks to be compressed unevenly. But, most importantly, now the valve slides in and out when moved by the control lever. My next task is to identify the spring and how it can be replaced. Looks like a cotter pin holds it on the end of the valve, but not sure how the forward end of the spring lies.

Thank you so much for your advice. I am making progress, definitely.

 

[Grass Roots Farmer]

I just looked in the Parts for my TO-20. Do I want the Hydraulic Control Valve with slotted end part # S 17266? Actually, all I need is the spring. Might that be available separately?

 

[Jerry/MT]

Glad you"re making progress. Hang in there!

 

[Jerry/MT]

I don"t think you"ll find parts to service the valve. You"ll probably have to buy the whole valve assembly. There is a part number for the spring, however. It"s 181 084 M1 and the TO-20 valve assembly is 181 088 M91.

 

[Jerry/MT]

I don"t think you"ll find parts to service the valve. You"ll probably have to buy the whole valve assembly. There is a part number for the spring, however. It"s 181 084 M1 and the TO-20 valve assembly is 181 088 M91.

 

[Grass Roots Farmer]

I just wanted to report that I fixed the problem. I ordered a new control valve from Steiner Tractor Parts, which came in 4 days. In that time, I bit the bullet and cleaned out the chambers of (probably) decades of crud, using diesel fuel and old rags. Today I replaced the valve, poured in new hydraulic fluid, sealed her up and crossed my fingers. She ran great and the hydraulics are smoother than before. The spring in the T-assembly had broken in half and seized up in the port.

Thank you all. I put the tractor right to work bringing in our hay rolls.