Power Steering & FEL on Yanmar F16 project

[jimmer2880]

Jimmer,
Great project. Thanks for all the pixs, great learning tools.
Was studying your hydraulic layout and need some help. In the upper right, blue "hard line from pump", pressure side of pump? Lower left, "transmission plug", return to tank? Am I correct?

Yes, that is correct.

If so are the "P"(pressure) and "T"(tank) ports on the steering valve switched or am I missing something?

I would think that "P" meant Pressure and "T" meant Tank. However, after consulting the hydraulic schematic, and with the guy who sold the unit to me, the "P" actually goes to the Tank, and the "T" is the Pressure to the pump. It doesn't make any sense to me though. Hopefully it's not backwards. That could sure get costly when I fire this puppy up. The pump is a standard Sauer Danfoss pump.

Here is the schema out of the manual that came with the Orbital Hand Pump

Also are there more line that are not shown on the 3pt valve, I don't understand it.

I'm not sure what you mean? There aren't any more hydraulic lines on my 3pt valve.

Thanks, keep up the good work

DRL

Thank you. Hopefully, we'll see how accurate I was soon

 

[DRL]

Jimmer
The diagram of the pump shows a check valve at the "P" port that will only let oil in, so that tells me it IS pressure. Also look at the pressure relief valve, if "T" was input it would not work, the spring and oil pressure would both be on the same side of the piston.

DRL

 

[DRL]

Jimmer
As for the 3pt valve I was thinking of the line(s) to the cylinder, and a return line.

DRL

P.S. Just thought of something, the "3pt valve" is the 3 point hitch valve correct? Or is that what is messing me up?

 

[jimmer2880]

Jimmer
As for the 3pt valve I was thinking of the line(s) to the cylinder, and a return line.

DRL

P.S. Just thought of something, the "3pt valve" is the 3 point hitch valve correct? Or is that what is messing me up?

You are correct, that is the 3pt hitch valve. So, there aren't any lines going into, or out of that for the 3pt itself.

 

[jimmer2880]

Jimmer
The diagram of the pump shows a check valve at the "P" port that will only let oil in, so that tells me it IS pressure. Also look at the pressure relief valve, if "T" was input it would not work, the spring and oil pressure would both be on the same side of the piston.

DRL

Well then, I'm glad you asked me about it. When I read the meaning of the "Y" symbol as "non-return", I thought that meant "non return from the tank".

Looks like I'd better go swap my "P" & "T" lines on the tractor before I fire the puppy up

I am very very glad that someone who knows more about hydraulics than I do looked at the diagram

 

[jimmer2880]

I have updated the diagram.

Here's the new one (since the link doesn't seem to be updating in the one above)

 

[DRL]

I'm no expert either but that is the way I read it. I would hate to see anybody blow up a good piece of machinery.

DRL

 

[DRL]

I take it the 3pt valve is attached to the side of the main housing so the rest of the ports are internal. I just can't figure out the "O" and "I" ports and direction of flow.

DRL

 

[jimmer2880]

Yes, the 3pt spool is attached to the rear end. So, the rest of the parts are internal.

The way the tractor was shipped, there was only 1 line running into that spool, the 12mm Hard line. However, the spool has 3 ports on it which have the letters I and O cast onto them. One of the O ports are for single acting cylinders. I'm leaving that one plugged. I'm using the other O port to power the PS & FEL. However, before using that port, an internal port must be plugged with a #2 (1/4) headless BPT (British Pipe Tapered) plug (allen set screw). Once the internal port is closed, the flow is directed out the "O" port, through the PS & FEL and back into the port with the "I" cast on it on the spool.

Does that help?

 

[DRL]

Thanks, now it is starting to make more since.

Keep up the good work

DRL