Aico Control Valve Model 100 Loader

jim249 · May 23, 2015

Hi All; This is my first post here! Any way, my neighbor has an older Massey Ferguson tractor with a Davis model 100 loader and a Aico control valve. The valve is acting as a da for the bucket dump and sa for the lift. He replaced the cylinder for the dump portion and it looks as if he took the top of the loader valve off since there is a home made replacement gasket under the top plate. I have searched the net for any kind of schematic for this type of valve and have come up empty. The problem is that the bucket dump portion of the valve is not working. I do know a thing or two about hydraulics, but am leery about taking this apart with out some kind of guidance. Could some person give me some ideas about how this valve works? Such as the adjuster on the bottom? There must be quite a few parts inside. Thanks for any help!

jim249 · May 23, 2015

After much searching, I found a parts picture for a Aico valve off the 101 and 102 loader. The bolt on the bottom I am guessing is the max pressure adjustment. Does any one know if the internals are going to be the same? Thanks for any help!

Leejohn · May 24, 2015

Can you make a drawing where the hoses go from cyl to valve and post it?

jim249 · May 24, 2015

Leejohn said:
Can you make a drawing where the hoses go from cyl to valve and post it?

Looking at the third picture of the hoses, the top left hose is the pressure in from the pump, the bottom left hose is for the sa lift cylinders, the two hoses on the right are for the da bucket cylinder.

Leejohn · May 24, 2015

Well you got me I can't see it working at all. It looks to me you are putting pressure into a work port and that would drive a sa cyl out, but no way to come back in. The boom cyls doesn't look like they can even get any pressure at all.

jim249 · May 24, 2015

Leejohn said:
Well you got me I can't see it working at all. It looks to me you are putting pressure into a work port and that would drive a sa cyl out, but no way to come back in. The boom cyls doesn't look like they can even get any pressure at all.

If you look at the first picture, you can see how the control valve is mounted to the lift frame. The lift frame is where the reservoir is. So the return is through the valve body into the lift frame.