FEL Valve Port Identification?

[IH Steve]

I have a valve for a Ford 770A FEL. There are 3 ports at the bottom of the valve, one has a (T) which I believe is for the return to the tank, another has a (P) which I think is a pressure port, and the third has an (N) which I have no idea?? There is also a fairly large plug at the top of the valve, maybe 3/4' in diameter, not sure about this one either. Maybe an adjustable relief valve??? All help is appreciated!

Thanks, Steve

 

[J_J]

A picture of your valve would be nice. Take off the pug on the top, and see if there are any springs and shims. If it is , that is your relief. There should be some more ports to operate a cylinder. Sometimes there are two return ports. Looking at the below valve, you see in port, out port and 4 work ports, plus several plug type fittings. One of those might be a PB port. Never seen the N designation.


https://www.surpluscenter.com/item.asp?UID=2009100212153771&item=9-7692&catname=hydraulic

 

[kennyd]

T or O=Tank or OUT-goes to the sump
P or PB=Power Beyond-goes to the next valve in the series
I or IN=Input from the pump

never heard of "N" before

 

[IH Steve]

Wish I had a picture for you.. I have the 4 work ports figured out and believe the pressure and return ports are correct. To help clarify things a bit I 've attached a diagram of the hydraulic system. At present I've plumbed the (P) and (N) ports from the FEL to the 2 ports indicated on the diagram. This obviously is less than desireable as valve the rear lift has to be actauted for the FEL to receive any pressure. Not to mention the hydraulics are having to work against the relief valve for the entire time. What I was thinking of doing is to install a cut off valve at the pressure line near the pump, then a QD between the cut off valve and the pump to supply the FEL. Just not too sure about this (N) port. When I removed the loader from the other tractor there was, or at least I THINK it was, a diverter valve or something similar. The line from the pump went to this diverter valve with 2 lines going from there to the (P) and (N) ports of the loader and then another line going from the diverter to the 3PH. I'm not a hydraulics guru as you've probably guessed already.

Steve

 

[kennyd]

Steve,

Without knowing what that N port is we are all just guessing...I would suggest using air pressure at this point to do some testing. Using the system the way you described is sure to cause a failure.

In a perfect world the pump should be hooked to the IN of the valve, the OUT should go to the tank, and the PB should go to the 3PH.

 

[J_J]

Normally, you would have the fluid go to the FEL first, and then sent to the back through a PB port. The fluid should go through all valves in a loop, and back to tank, so that which ever valve in the circuit is operated, will have control. The first valve in line has priority. There are many different way to hook things up, so lay out a good plan and install to suit your needs.

I am thinking that the "N" actually means IN .

Port Designation
Working lines A, B, C and so on

Pressure (power) supply P

Exhaust/Return R, S, T and so on

Control (Pilot) Lines (T normally used for hydraulic systems, R and S for
pneumatic systems) Z, Y, X and so on

 

[IH Steve]

I guess if I installed the cut off valve and the QD and went to the (P) port and then a pressure gage at the (N) port, that would tell me something.. Does that sound safe??

 

[kennyd]

You are playing with fire, running the risk of deadheading the pump and grenading it.

Test the valve with air to figure out the ports...then you can hook it up with knowledge instead of guessing.

 

[J_J]

I just saw that you already had a "P" pressure port, so disregard my "N" comment. Use air, and you just might have to plug that port. If you put fluid to the valve without knowing exactly what the port is. ??? Sometimes, the valves have two tank ports.

 

[IH Steve]

I'll give that a try.. Def dont wont to blow anything up!

J.J.- the breakdown of the port ID's is good information.

Thank you both!
Steve