what would be the risk if were to instal?

[J_J]

With that drawing, you have no 3pt. If you have a hyd valve with no PB outlet. the main flow and cyl expended fluid exits out the OUT/TANK port. If you want 3pt, then you have to use the OUT port of the tilt valve to pass fluid to the 3pt.

If your 3pt should fail and cause some high pressure backup to the system, you could crack a valve.

Nobody, not even the manufactures want to address the back pressure issue on the tractors hyd valves. Everybody knows the PB port is designed to take full pressure, and the Tank valve has limited pressure rating.

A question might be, what is the relief valve setting on the 3pt. Is it anywhere near the FEL valve PRV pressure setting, if so, then when the 3pt goes into relief, full system pressure is felt through all the valves.

You guys that test valves, do you ever test the valve with full pressure on the IN and OUT port? Does the 3pt cyl allow the pressure to build up to full system pressure?

 

[J_J]

deepNdirt,

Do you know why the 3pt would operate only when using the FEL?

What I am thinking is that you connected the out port of the FEL to the 3pt, and sent the PB to tank/reservoir. So when you operated any cyl on the FEL, the expended fluid from the cyl flowed to the 3pt only when the levers on the FEL was operated. So any time you needed the 3pt, you raised the lift arms or curled the cyl. If at any time you stopped the FEL, the 3pt also stopped. That is my take on it anyway.

 

[deepNdirt]

With that drawing, you have no 3pt. If you have a hyd valve with no PB outlet. the main flow and cyl expended fluid exits out the OUT/TANK port. If you want 3pt, then you have to use the OUT port of the tilt valve to pass fluid to the 3pt.

If your 3pt should fail and cause some high pressure backup to the system, you could crack a valve.

Nobody, not even the manufactures want to address the back pressure issue on the tractors hyd valves. Everybody knows the PB port is designed to take full pressure, and the Tank valve has limited pressure rating.

A question might be, what is the relief valve setting on the 3pt. Is it anywhere near the FEL valve PRV pressure setting, if so, then when the 3pt goes into relief, full system pressure is felt through all the valves.

You guys that test valves, do you ever test the valve with full pressure on the IN and OUT port? Does the 3pt cyl allow the pressure to build up to full system pressure?

JJ
so I can use the out port of the tilt valve to connect back into the inlet line to the 3 pnt valve? this is what I have drawn, maybe cannot see the 3 pnt valve but this is where the end of the series line kills into attached to the tank, will there be enough pressure from this line to operate the 3 pnt lift?

 

[J_J]

Hyd pressure only occurs when there is a resistance to the flow of fluid. If no other valve is being used, pump flow is passing through all the valves and the 3pt can develop full system pressure, or up to the relief pressure. If any other valves ahead of the tilt valve is activated, there may not be any fluid left for the 3pt. The activated valve will use the fluid and then send it through the OUT/T port to the reservoir, leaving none for the 3pt. If a valve up stream is only using some of fluid, then any other valve will have fluid to operate, using what is left over from pump volume.

 

[deepNdirt]

JJ
you are very good in explaining things and I do appreciate your patients, it is me lacking the comprehension skills of the hydraulic world
let me try asking again in another way, If the rear tilt valve does not have a PB port but yet only has the return port, will this port alone feed an adequate supply of Fluid into the 3 pnt valve to make the lift work properly?

In a real life scenario where i would be working the tractor......
I would back up to where I need to drag drop the bucket/3 pnt lift to the ground, then apply the rear tilt and start pulling, so as i see it I could never be operating any 2 controls at one time,
So would this allow the fluid to continue through all valves making it to the 3 pnt lift allowing full operation of the lift?
without any need for a PB ......

Thank you

 

[J_J]

You can use that valve in series to provide fluid to the 3pt. A lot of valves do not have a PB port, and are connected to the 3pt. It all amounts to, whether or not the OUT/T port can handle the pressure, and it seems that valves in the past have done just that.

 

[deepNdirt]

You can use that valve in series to provide fluid to the 3pt. A lot of valves do not have a PB port, and are connected to the 3pt. It all amounts to, whether or not the OUT/T port can handle the pressure, and it seems that valves in the past have done just that.

:thumbsup: Great! it sounds like I might have a chance of it working and eliminating that dump hose I've always hated being there,
there is one other thing I need to ask.... on the plugged ports, the ones I had asked about using for the supply lines into the cylinder..... well I opened them up and found a Ball and pin in each one of the ports, If using these ports I suppose I should move these balls over into the side ports and use the plugs on these ports... right? wrong? looking into the ports the holes on the side seem to be much shallower, and doesn't appear that the pin would fit deep enough to close up these ports. Oh! and the reason for needing to swap ports is the existing ports will be on the side that the lift arm will be passing very close by and possibly hit.. depending on the adaption I would have to use..... so it would be much easier to simply move to the rear ports if at all possible.
Please advise...
Thanks once again

 

[J_J]

Most valve have load checks, and relief valves usually have a spring and ball or something similar. Don't know exactly what those ports are. Maybe someone will recognize that valve and comment.

 

[deepNdirt]

Most valve have load checks, and relief valves usually have a spring and ball or something similar. Don't know exactly what those ports are. Maybe someone will recognize that valve and comment.

Thanks JJ,
here is a closer look at the valve and the concern I have with the lines,
to be honest with you I didn't even give it a thought about how close the lift pin would be...until after I actually mounted the cylinder and raised it to top position if worst case and cannot move to the other ports, I could try and limit the lift hight somehow... as I never bring any implement up that high anyway,

 

[J_J]

You might want to consider another place for that valve.