Ford 1710

[larryvreyes]

Why does the 770 loader start to raise up when the downward float is engadged ? It only does that when the 3 point lever is in ful raised position .

 

[RickB]

You are flooding the loader return circuit with oil that is bypassing the relief valve because you are putting the hitch lever in the "test" position. Don't do that.

 

[J_J]

Why does the 770 loader start to raise up when the downward float is engadged ? It only does that when the 3 point lever is in ful raised position .

When you raise the 3pt, and the relief activates, you are pressurizing the supply hose from the pump, including the FEL valve..

The loader valve lift spool is in float, and in the float mode, the cyl are open to the pressurized fluid.

When you put the 3pt back to neutral, the pressure is released and the lift arms should fall/float.

 

[RickB]

When you raise the 3pt, and the relief activates, you are pressurizing the supply hose from the pump, including the FEL valve..

The loader valve lift spool is in float, and in the float mode, the cyl are open to the pressurized fluid.

When you put the 3pt back to neutral, the pressure is released and the lift arms should fall/float.

Not so. If the loader spool is in float, the work ports are isolated from the supply port and open to the tank port. Every time, no question.

 

[J_J]

FLOAT SPOOL (POSIT10N): A spool valve design which connects [ all ports ] to the tank, usually in a detented fourth position, allowing a cylinder or motor to "float"

All ports does not include PB.

However, if you block the flow as in a FEL valve with out PB, what
happens. The fluid will find the area or least resistance and that is probably the work ports.


So what you are saying, is that if I am using FEL float, I can not use 3pt.

You might be right, I will check it out.

I did check .

If the valve has PB, and in float mode, the PB fluid will go to 3pt.

If you activate the 3pt, the pressure will back up and probably go to the work ports of the cyl, because the tank ports and the PB ports are separated.

As soon as you release the 3pt lever, you open the circuit and the pressure from the loader lift arms/bucket will force the bucket back down to true float mode.