Loader Valve Test Port Location

[Thumbs Up Farm]

I have a Massey Ferguson 40 with an MF 34 Loader. Can someone tell me which plug (by the number on the picture) I would use to install a test gauge to measure the pressure on this valve (see attached picture)? This is the loader valve from a Massey Ferguson MF34 loader. I need to determine what the relief valve pressure is set to in order to match my remote power beyond control valve relief and insure I have adequate hardware/pressure configuration.

Thanks,

 

[J_J]

Does this valve provide in flow to the loader valve, or where does the flow for the loader valve come from?.

The hyd gage normally goes in a tee in the IN port of the loader valve.

Is your input to the valve the square part of the valve.?

You might could use

72,74, 75

If you have a hose from an external pump, you can use a tee in the output/pressure hose.

Hydraulics:
Type: open center
Capacity: 8 gal [30.3 L] (tractor)
6 gal [22.7 L] (loader)
Pressure: 2125 psi [146.5 bar] (loader)
Total flow: 20 gpm [75.7 lpm] (loader)
Steering cap.: 1.6 gal [6.1 L]

There are also work port relief in that valve.

You would set your remote relief valve at 2125 psi to equal the loader PRV.

 

[Thumbs Up Farm]

Thanks j_j,

The inlet is the unmarked port at the front adjacent to plug 75. This port is fed by a hard line coming from the front mounted pump. There is no "T" in this line to mount the gauge to and installing one would be a pretty good project on its own.

I have Big Deans CD which shows this loader valve, describes how to change the relief settings, and mentions a test port on top of the valve to screw in a 1/4"npt gauge to read the settings. His illustration(s) do not show the location of the test port which leaves me confused

I also have some confusion as to the relief settings, as you mentioned above, the system pressure shows 2125psi from TractorData, however, Big Dean recommends setting the relief to 2500psi. So, either Dean has the wrong setting in his notes (perhaps typo should be 1500psi??) or Tractor data has the wrong data on the pump pressure. Therefore, I need to measure the relief pressure and set my remote valve and system accordingly. I have no intention of changing the current settings since this tractor is old, is all working fine, has plenty of power, and is not leaking. I do have an issue with the bucket curl not holding the position, but I suspect it needs some o-rings which I plan to replace during this Power Beyond project.

Anyway, I plan to use the power beyond port to power a post auger and a grapple. I was hoping that someone well versed on Hydraulics, such as yourself, might offer some insight. Thanks again for taking the time to respond. Any further info will be greatly appreciated.

 

[J_J]

#74 is a 1/4 hex plug, and could be the gage port.

It will not hurt to try it as it is a plug.

 

[Thumbs Up Farm]

Looks like there may be two #74 I will have to take a look at the valve to see but looks like I will need a short pipe/nipple to get the gauge up high enough to install.

I asked his on the Massey Ferguson forum, but do you have any experience attaching to the pressure beyond port on these? Here is the link to the other thread. http://www.tractorbynet.com/forums/massey-ferguson-owning-operating/292098-massey-ferguson-40-power-beyond.html

 

[J_J]

Each spool has a #74.

The upper spool assembly shows the hex plug, but not the number 74.

No experience with your valve , just using common sense and some hyd knowledge.

 

[Thumbs Up Farm]

I looked at the plug 74 on the lower spool (Bucket Dump) and it appears accessible. The upper spool plug appears to be hidden underneath the control lever bracket. Does it matter which port I use to test the relief pressure settings? Any special instructions?

BTW I have more info on the Power Beyond issue http://www.tractorbynet.com/forums/m...er-beyond.html

Also, since I am into working on this loader valve. I would like to resolve a couple of other issues.

1.) The bucket dump spool (#2 in picture above) will not hold its position and constantly tries to dump.
2.) The boom lift spool (#3) deadheads/loads the pump when trying to lower the lift.

I am fairly certain that neither of these issues are caused by a bypass in the cylinders. The dump cylinders have been replaced with new ones and the lift only causes the pump to be loaded when it is being lowered not when it is being raised.

Can anyone provide any insight on these two issues?

 

[Tx Jim]

Thumbs Up Farm
If cylinders aren't bypassing internally you need a new valve.

 

[Harry in Ky]

I agree with Jim. You're just wasting time here. Toss that thing in the scrap bin and start over. You mentioned at some point wanting to add more valves/functions anyway, right? I'm sure you will get a ton of suggestions as to what to look for, so pick something that suits your budget and skill level and go with it.

 

[J_J]

Your boom lift problem is probably caused by a bad QD, and this should cause the relief valve to open.

You will not dead head the pump, but the relief will activate.

A bucket that will not hold probably has some bad seals.

Can you activate the relief with the curl circuit?

Plug 73 is a body plug, so it might also be a good gage port.