JD 2120 3 pt won't lower

[cowboyup1717]

I have a 1971 2120 in decent shape. Today I was putting a blade on and all was working fine till I went to lower it. Nothing. Won't raise or lower. All other hydraulics work fine, like the loader. I need help.

[wyeguy]

Is there a control knob that let's you adjust the rate of the 3pt drop? I think if that accidently gets adjusted all the way closed, the 3 pt won't lower.

[cowboyup1717]

There is a rate of drop adjustment in the center of the transmission. I messed it some but no change. It's like it was welded in place

[wyeguy]

I don't think a clogged filter would only affect part of the hydraulics. Maybe a clogged line or something. Someone with more experience will be more help. Sorry!

[cowboyup1717]

Thanks

[wyeguy]

There's another similar thread about a 3pt issue. Scroll through the recent posts. The latest was a couple hours ago. One in part said "Check the fluid level. If ok I would suspect the priority valve has crud in it dumping to steering. Had this happen with mine. Took it off, disassembled, cleaned with brake cleaner, and replace."

[cowboyup1717]

I'll look into that

[Tx Jim]

Check rate of drop screw under the seat to be sure it's not completely closed. Do other hyd functions operate properly? Check frt hyd coupler to be sure it's intact. It's remotely possible that some of the linkage in photo has become loose. Where is L/D control lever adjusted? Put it in "D" if mot already there.

[cowboyup1717]

The whole drop rate control was loose. The whole unit comes out when turned. I take it only the top threaded screw is suppose to turn? Would that cause air to get into the system?

[Tx Jim]

On rate of drop screw bolt(parts key #8) screws down against the ball(parts key #6) to block(partially or complete) the return oil port in the piston housing. Air normally enters hyd system from a leaking suction tube on trans pump. I'll ask again: where is the draft control lever setting?? If it's setting anywhere else but "D" then set it in "D".