FEL valvle problems dongfeng ZB25

[Platyphylla]

I had to replace the original 4 in 1 FEL valve on my dongfeng zb 25.
I cant get the loader to work. The P and T hoses flex with any directional movement and the bucket etc move slightly when using the controls. I notice the correct directional movement occurs very slightly but only in a very narrow band about half way through full movement of a control lever. Pressure will remain in the work hoses after shutdown until I move the levers back and forth. The 3pl is working fine.
The replacement valve is different to the original. I have asked a couple of times what the brand is to see if I could find an operational diagram but for some reason (commercial?) the question has been ignored. Unfortunately the tiny brand sticker got knocked and erased on installation.
Two photos: the first (taken from another post on this site) is the original valve. The second is the replacement.
I have configured the work hoses exactly as they were on the original valve. The P and T hoses are connected as shown in the second photo.
Is it possible that the work valve pairs can be reversed on different brands of valves (the hoses to the top and bottom of a cylinder)? And if so could this be the problem? Could there be another reason the loader valve is not working? I know for certain the cylinders and bucket are not seized.

 

[oldnslo]

If both the P & T hoses flex this would indicate pressure in the "T" line which would limit the loader movement. Did the new valve have an option for Power Beyond (PB) port and another "T" port? If yes you will have to connect the "T" port directly to tank. Some valves will not handle down stream pressure in the tank line and that is why they have both the "PB" & "T" ports.

 

[J_J]

If you have any QD's, reset them.

The return needs an open passage to tank.

Do you have a PB outlet?

On the work ports, you could have the left side opposing the right side, and try to flex the bucket. Otherwise, one cyl is pushing and the other is pulling.

Install a hyd gage and use it for trouble shooting.

 

[Platyphylla]

Thanks so much for the reply and apologies for the slow response. Between horses and people there have been some sad things to deal with.
Turned out, of all the possibilities (there are 5 separate ports to place a pump or tank hose), the configuration I thought I had tried and had not was the correct one or as Murphy would dictate, the last one.

Another question. I am not up on pump terminology...what is the function of the adjustable screw with a locknut. Can be screwed in or out for about 2". It is located in the upper left of the valve just behind the pump hose in photo 2.

If you have any QD's, reset them.

The return needs an open passage to tank.

Do you have a PB outlet?

On the work ports, you could have the left side opposing the right side, and try to flex the bucket. Otherwise, one cyl is pushing and the other is pulling.

Install a hyd gage and use it for trouble shooting.

 

[J_J]

All I see is a silver can cover for the float assembly on the bottom of the valve.

The only adjustable item on the valve should be the relief valve, and is usually close by the IN port.

Do you have the PB adapter and is it installed.

This should be your configuration.

Pump to IN port of loader valve.

Tank port to return hose.

PB adapter installed and this hose goes to the hyd block or the remote valve or 3pt.

Work ports connected correctly.

 

[Platyphylla]

Thanks JJ. I did reply before but must not have pressed the wrong post button. I think the part I am describing is located near the base of the float assembly in the photo. The dark part being the locking nut. It is near the pump in port so must be the relief valve. What's the function and best setting?
No PB adapter. Have pump in, out to tank and 6 work ports for the FEL. There are 5 ports for the larger hydraulic hoses (like pimp, tank etc). Don't have a clue what they are. One must be a PB port.

 

[J_J]

The function of the relief valve is to relieve over pressure to protect the hyd components.

Your tractor manual should have the correct pressure setting, probably around 2500 psi.

In the picture, the hose with the 90 degree fitting sitting on a fitting, that I believe is the PB adapter, and the other port is the tank port.

The PB port will have either an adapter like this or a 1/4 in hex screw.

 

[Leejohn]

Are you sure that fitting in the out port is not a PB adapter. Did that come with the new valve? The fitting that you have the 90 deg. stuck in looks like it could be a PB fitting.

 

[Platyphylla]

The manual is pretty hopeless since it does not include the valve or the FEL. They did send me an east wind manual for the new valve that I am yet to read.
The 90deg fitting comes straight from the hydraulic pump at the side of the engine.
There are another three 1/4 plugs that would fit the pump and tank hoses.
I thought PB was 'Power Beyond' for things like a backhoe?

The function of the relief valve is to relieve over pressure to protect the hyd components.

Your tractor manual should have the correct pressure setting, probably around 2500 psi.

In the picture, the hose with the 90 degree fitting sitting on a fitting, that I believe is the PB adapter, and the other port is the tank port.

The PB port will have either an adapter like this or a 1/4 in hex screw.

 

[Platyphylla]

PS. The valve just came with a couple of open ports (pump and tank), open work ports and plugs in the other three ports. Plugged ports are located at the very top near the pump port and two under the valve near the tank port. They had the top port open (can't see it in the pic) and the tank port. After that did not work and several calls later they gave me the photo above. That was the only configuration that worked.