Ford 1520 Hydraulic problem.

[acro]

Yes it should be in the operators manual and it is unknown about the pump until it is plumbed properly and see how it operates.

Well, it's worked for years the way its currently plumbed.

It's possible that it's plumbed "incorrectly" due to me using a closed center valve I had on hand, rather than buying the "correct" open center one. Again, I'm not sure and out of town until Friday.

 

[TheOldHokie]

Well, it's worked for years the way its currently plumbed.

It's possible that it's plumbed "incorrectly" due to me using a closed center valve I had on hand, rather than buying the "correct" open center one. Again, I'm not sure and out of town until Friday.

Hopefully you dont have a closed center valve on your open center tractor. That would subject the pump to constant maximum pressure whenever the selector is in the implement position and kill it over time. Post a picture of that valve if you have any doubts.

You apparently have an open center directional valve connected to the.P and T ports on the hudraulic outlet block. That short circuits the open center hydraulic system on the tractor and has never actually worked correctly. You have worked around that by fiddling with the selector and operating multiple valves at the same time. There should be no need for that.

Move the bottom right hose on the outlet block to the upper left port as Mark has described and put the selector valve in the "implement" position as shown in your manuals. That is the correct open center plumbing.

Connected like that the pump, 3pt, and add on valve will all be in series and both valves should work independently with no need to ever touch the selector.

If things arent working after moving the hose the next step would be to put a pressure gauge directly on the P port and see what the pump is doing. It may have finally given up the ghost.

Dan

 

[mhb@ufe]

Well, it's worked for years the way its currently plumbed.

It's possible that it's plumbed "incorrectly" due to me using a closed center valve I had on hand, rather than buying the "correct" open center one. Again, I'm not sure and out of town until Friday.

From your previous posts it has not been operating correctly for years and I would be concerned that you have damaged the pump now. You need to verify which valve you have (open or closed center). If it is closed center you need to change to an open center and get it plumbed correctly. Some valves have a closed center plug that can be removed to make it open center.

 

[TheOldHokie]

Well, it's worked for years the way its currently plumbed.

It's possible that it's plumbed "incorrectly" due to me using a closed center valve I had on hand, rather than buying the "correct" open center one. Again, I'm not sure and out of town until Friday.

You cannot use a closed center valve on that hydraulic system. It will over pressure the pump and kill it sooner or later.

The valve must be open center and may or may not have a power beyond port The tractor hydraulic outlet is set up for use with a power beyond type valve which is preferred but you can cheat and use one without. It appears yours is open center without power beyond. If you have any doubts about what you have post a picture of the valve.

Here is a cheat sheet for connecting your auxiliary valve. You can daisy chain as many as you want together as long as you follow this template. I am a little concerned about what you were doing with the log splitter you mentioned earlier. It gets added and subtracted just like any other valve.

Dan

 

[mhb@ufe]

Rotating the slotted valve on the diverter block clockwise is for normal operation without any auxiliary hydraulics. Rotating it counter clockwise would be to supply oil to the auxiliary valve which must be an open center valve as already stated. With it properly plumbed there will be no need to turn the valve regardless of which function you are operating.

 

[acro]

Oh my. Just got home, haven read recent posts yet, but will as soon as I sit down for the evening.

I had capped the aux line connections(S & O) off in anticipation of checking some pressures. And I had a spare filter, so I changed it thinking I'd try it again.

But I cut the filter 1st.

Seems futile to troubleshoot further.
I need to replace the pump and drain/flush the system.

So, recommendations on pump source?

 

[Tom in Mo.]

Ouch. You got a mess. Try Weavers Compact Tractor Parts near Shippensburg, PA. Keep in mind that what you see is on the suction side so when you put a new pump on and plumb the system correctly, you will be flushing and changing that filter several times.
https://compactractorparts.com/

 

[acro]

Rotating the slotted valve on the diverter block clockwise is for normal operation without any auxiliary hydraulics. Rotating it counter clockwise would be to supply oil to the auxiliary valve which must be an open center valve as already stated. With it properly plumbed there will be no need to turn the valve regardless of which function you are operating.

But the valve rotates 360. Always has.

 

[acro]

That block has three ports

P - is the pump pressure outlet for an auxiliary implememt

N - Is neutral or pressure beyond return from your implement and powers the 3pt.

T - tank rreturn from your implement.

When no implement is attached to P and N pump pressure goes straight througjh the block to the 3pt via the other hard line.

When you connect an implement (e.g. loader) you turn the selector valve to divert fliow out P and flow must be returned to N where it continues to the 3pt as above. The selector valve should stay in that position as long as the implement is attached. If the implement is disconnected the vslve must be switchef back to the straight through position.

So what is hooked to those two hoses? Hopefully it is your loader valve.

And where Is the relief valve you checked?

Dan

My valve definitely has O & S, which I connected to. The 3rd port doesn't seem to have a legible marking.

They seem to match up with T & P from a previous drawing

 

[mhb@ufe]

But the valve rotates 360. Always has.View attachment 76833

That's another problem you should address as it should not turn 360 degrees.

 

[mhb@ufe]

But the valve rotates 360. Always has.View attachment 76833

On the back side of the diverter block there should be a roll pin through the spool and 2 roll pins in the block that limit the rotation of the spool.

New Holland Agriculture | Schematic, Manuals, Specifications and Diagrams for manifold diverter block - sba340013420 | MyCNH US Store

Find schematics, manuals, specifications and diagrams for MANIFOLD DIVERTER BLOCK - SBA340013420. Find genuine OEM parts for your needs.

www.mycnhstore.com

 

[TheOldHokie]

My valve definitely has O & S, which I connected to. The 3rd port doesn't seem to have a legible marking.

They seem to match up with T & P from a previous drawing View attachment 76834

My valve definitely has O & S, which I connected to. The 3rd port doesn't seem to have a legible marking.

They seem to match up with T & P from a previous drawing View attachment 76834

Your manual is your friend and you need to consult it.

The P, N and T labels are taken from multiple different pages of the CNH parts diagrams and are standard in the industry. I understood the meaning immediately. I have never come across O and S. The locstion of the hard lines attached to the block seem to match the P and N labels.

I think I would have a peek inside the intake and exhaust ports on that pump to see if that trash in the filter is coming from the pump.

Dan

 

[TheOldHokie]

Oh my. Just got home, haven read recent posts yet, but will as soon as I sit down for the evening.

I had capped the aux line connections(S & O) off in anticipation of checking some pressures. And I had a spare filter, so I changed it thinking I'd try it again.

But I cut the filter 1st.

Seems futile to troubleshoot further.
I need to replace the pump and drain/flush the system.

So, recommendations on pump source?

View attachment 76824View attachment 76825View attachment 76827

You said you checked the relief on the outlet side of the pump and found no sign of that stuff? Seems significant. I would not be so quick to jump to conclusions.

You clearly need to drain and flush the system, replace the filter, and refill with new clean oil.

Then I would read the manual to make sure I had the selector valve set ti the implement position, remove the cap on just the P port, and check flow pressure at the pump outlet port.

Dan

 

[acro]

Yea. Oil on dipstick looks good too.

That "filter" is a strainer. It's been a very long time since I had changed it. I might guess that it's sized large enough to allow the oil to slow down enough to let everything settle out in it. And that trash has been accumulating for a while.

The oil was normal looking when I was unscrewing the filter and initially when I poured it out.

I'll know more after work when I tear into it.

 

[TheOldHokie]

Yea. Oil on dipstick looks good too.

That "filter" is a strainer. It's been a very long time since I had changed it. I might guess that it's sized large enough to allow the oil to slow down enough to let everything settle out in it. And that trash has been accumulating for a while.

The oil was normal looking when I was unscrewing the filter and initially when I poured it out.

I'll know more after work when I tear into it.

You appear to have a paper element suction side filter as opposed to a wire mesh strainer. That filter will clog up and restrict flow to the pump if not maintained. The parts diagram also appears to show a mechanical bypass valve in the filter head that will open and allow unfiltered oil through if the filter gets totally clogged.

It looks like your filter may be clogged and cutting off supply to the pump. Thats good news because it offers a chance the debris is from something "normal" like wet brakes and the pump is not yet damaged. The system needs to be thoroghly flushed and that is hard to do without a working pump.

Hopefully you can get things reasonably clean by draining and refilling. Then put on a new filter and with thecselector set to the implement position see if you are getting flow out of the P port on the outlet block. You can do that by hooking up a hose, sticking the open end in the hydraulic filler, and starting the engine. If you get flow and the oil looks OK hook a pressure gauge to the hose and test pump outlet pressure. With the gauge connected the pump will be unloading through the relief with so you dont want to run the engine any longer than it takes to see the pressure.

If you are lucky the pump is OK and you can turn your attention to fixing the hydraulic block plumbing and findig the source of the trash in the filter.

Dan

 

[acro]

No, it's a metal strainer, but built as a non serviceable screw on. I just took my new replacement off to double check it(different brand), and it's a metal mesh also.

Anyway, my pump looks a lot better than I had expected. I don't believe it warrants replacing just yet. I've seen inside lots of hyd pumps, and while there is some scratches on this one, there is barely a lip warn at the end plates.

I believe the problem is elsewhere since it occurred/got worse so suddenly.
What's the opinion here?

And mystery solved on the selector

 

[acro]

Regarding the trash, very well could have come from the previously mentioned log splitter.

But I'll get it cleaned up and see.

I checked that website out and they do have a choice of 2 pumps, but at this point, maybe just a seal kit which I didn't notice. I'll look around.

 

[TheOldHokie]

No, it's a metal strainer, but built as a non serviceable screw on. I just took my new replacement off to double check it(different brand), and it's a metal mesh also.

Anyway, my pump looks a lot better than I had expected. I don't believe it warrants replacing just yet. I've seen inside lots of hyd pumps, and while there is some scratches on this one, there is barely a lip warn at the end plates. View attachment 76968
View attachment 76969
View attachment 76970
View attachment 76971
I believe the problem is elsewhere since it occurred/got worse so suddenly.
What's the opinion here?

And mystery solved on the selector
View attachment 76972

I guess I did not look closely enough at your pictures.

Clean the sump out and put in new oil, fix the stops on the selector, put the pump back together, and correct the plumbing on the external valve. Should be better than ever.

Dan

 

[mhb@ufe]

Verify the positioning of the selector valve with air flow before installing a new roll pin to make sure you get flow in the proper direction.

 

[acro]

Well, I'm rather embarrassed to admit that I found the "sudden problem" I had. The position of my additional vlalve had completely slipped my mind. Its under my seat, and i guess it had been so long since I had used it, it never entered my mind. And it's not spring return.

But anyway, it's forced me to do some overdue maintenance, repair my selector valve, and learn.

I believe the O & S are markings for the position of the selector valve, and not the actual port markings. I'm waiting on some paint to dry before final assy, but I drained and flushed the case while removing the pto cover and cleaned that magnet too.

For now I'm going to leave my aux circuit capped off, as I don't use it anyway.