Question for Hydraulics Gurus

[Greybeard - PA]

Hydraulic test ports on the lower sides of 8N's can be used for one-way cylinders like Wagner loaders. We had one on a Jubilee when I was a kid on the farm. My own '51 N has a male quick connect in place for this purpose.

My question are about this port. What is it's purpose other than for external hydraulic work? Is it really a test port? If the quadrent valve controls things connected to this port, how can pressure also be fed INTO this port from belt driven pumps a 'la Messers. Allen/Sherman livee hdraulic systems? Has anyone ever seen a hydraulic flow chart that shows this port? The one in the FO-4 manual does not show this.

I'm hoping to learn about this. Please fill my cup with knowledge . . .

Thanks for your time,
Dave Erb
New Holland, PA

 

[souNdguy]

it is indeed a test port.

when the hytrol handle is lifted up, fluid is directed at the hyd cyl.. this port is in that high pressure circuit. that's why you can screw in a valve at this port and chain the lift arms down to the axles, and then pull the lift handle up, and observe what pressure the relief cracks at.. ( thus the relief is also in this sid eof the circuit, as it should be ). Now.. when you drop the lift handle, oil has another place to go.. it can exhaust thru an open valve instead of being forced against a piston.. thus if you introduce oil to this port, it has the same options available... it can, with the handle up, be directed against a piston or relief, or with the handle down, it can exhaust thru the same valve the oil coming from the 8n pump goes thru.

this is also why people that are using the add on hyds that dump into the test port sometimes experience lift arms that creep up even with the 3pt handle down.. ie.. so much oil volume is flowing that it cannot make it thru the exhaust valve without creating a little bit of pressure, which, as we saw earlier, has a place to go.. IE.. press against the relief.. though it can't open it.. and press agains thte piston, which it -can- lift slightly.. thus if you load your 3pt lift with say.. a back blade, the lift won't creep up with the extra flow and pressure from the exhaust valve.

hope this helped.

soundguy

 

[JMOR]

(quoted from post at 15:50:39 02/15/10) Hydraulic test ports on the lower sides of 8N's can be used for one-way cylinders like Wagner loaders. We had one on a Jubilee when I was a kid on the farm. My own '51 N has a male quick connect in place for this purpose.

My question are about this port. What is it's purpose other than for external hydraulic work? Is it really a test port? If the quadrent valve controls things connected to this port, how can pressure also be fed INTO this port from belt driven pumps a 'la Messers. Allen/Sherman livee hdraulic systems? Has anyone ever seen a hydraulic flow chart that shows this port? The one in the FO-4 manual does not show this.

I'm hoping to learn about this. Please fill my cup with knowledge . . .

Thanks for your time,
Dave Erb
New Holland, PA

little study of my art should explain most of your questions.

 

[TheOldHokie]

(quoted from post at 15:50:39 02/15/10) Hydraulic test ports on the lower sides of 8N's can be used for one-way cylinders like Wagner loaders. We had one on a Jubilee when I was a kid on the farm. My own '51 N has a male quick connect in place for this purpose.

Dave Erb
New Holland, PA

Actually it can be used as a source of hydraulic pressure to control just about anything you want. Chain the lift arms down and move the control lever to the top and you have a constant volume hydraulic pump discharging through the test port. Feed that discharge to any open center dirctional control valve and dump the return from the valve back into one of the inspection covers and you are good to go. Not a lot of juice (2.5 GPM at best) and the flow stops when you depress the clutch but wadda you want for 1939???

TOH

 

[TheOldHokie]

(quoted from post at 16:25:35 02/15/10)

(quoted from post at 15:50:39 02/15/10) Hydraulic test ports on the lower sides of 8N's can be used for one-way cylinders like Wagner loaders. We had one on a Jubilee when I was a kid on the farm. My own '51 N has a male quick connect in place for this purpose.

My question are about this port. What is it's purpose other than for external hydraulic work? Is it really a test port? If the quadrent valve controls things connected to this port, how can pressure also be fed INTO this port from belt driven pumps a 'la Messers. Allen/Sherman livee hdraulic systems? Has anyone ever seen a hydraulic flow chart that shows this port? The one in the FO-4 manual does not show this.

I'm hoping to learn about this. Please fill my cup with knowledge . . .

Thanks for your time,
Dave Erb
New Holland, PA

little study of my art should explain most of your questions.

Hey - so that's how the positon control on the 8N works :idea:

TOH

 

[Greybeard - PA]

Thank you all. Now I understand,
Dave Erb
New Holland, PA

 

[Hobo,NC]

Correct me if I am wrong

The check valve is the valve that connects to the tail of relief valve...

WARNING :shock: all I know I read on the Internet,,, do it enuff and you can become a guru also,,, not responsible for damages,,, I read it and just pass it along,,, proceed with caution

 

[JMOR]

(quoted from post at 08:58:27 02/16/10)

Correct me if I am wrong

The check valve is the valve that connects to the tail of relief valve...

WARNING :shock: all I know I read on the Internet,,, do it enuff and you can become a guru also,,, not responsible for damages,,, I read it and just pass it along,,, proceed with caution

I guess it depends on which end we call the head and which end we call the tail, but you know how I love pictures, so: