Using 3 Point Hydraulics with the loader off???

[knightgang]

L2950 with LA450 loader.

I removed my loader to have better access to do work around the radiator and water pump. My loader had two quick connect fittings on the hydraulic manifold on the tractor and one line did not have a quick connect. I assumed that one line was the Power Beyond line.

Anyway, I had heard that when you remove a loader, you have to turn a screw to change a valve setting so that your three point hydros will still function.

In the attached picture, I assumed that the line highlighted yellow with the blue arrow is the power beyond line. The screw circled in red would be the screw I would have to turn.

The screw was all the way to the left, and would only turn a quarter turn clockwise. With the line off, and the screw turned clockwise, it pumped fluid out, so had no choice but to turn it back to the left (counterclockwise) which is where it was already set with everything hooked up...

What am I missing? Shouldn't this screw allow flow when everything is hooked up.

Also, that one line that I assume is power beyond, can I put a quick connect on it as well? Seems to me it will make connecting and disconnecting even easier and keep the possibility of debris out of the system.

 

[knightgang]

Anyone else run their tractor with the loader off? What do you have to do to keep your 3-point hydraulics working?

 

[North Idaho Wolfman]

You either need a plug (BSPT) or a cap on the fitting for the line.
Then turn the slotted valve to the other direction to allow fluid to flow.

One critically important note:
You will burn up or blow a seal on the pump if you keep running it the way you, are as you are dead heading the pump.

 

[knightgang]

If I put a quick connect on that line, would that work, than just disconnect and turn the screw valve?


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[North Idaho Wolfman]

Yes that would be Ideal!

On the other end of that line (Yellow) was there a quick disconnect?
If there was will it connect to quick disconnect right above it?
If so then that's all you need to do, as that will connect the loop without having to change the selector valve.

 

[Tooljunkie]

You either need a plug (BSPT) or a cap on the fitting for the line.
Then turn the slotted valve to the other direction to allow fluid to flow.

One critically important note:
You will burn up or blow a seal on the pump if you keep running it the way you, are as you are dead heading the pump.

Didnt someone recently shear the pump shaft doing the same thing?

 

[North Idaho Wolfman]

Didnt someone recently shear the pump shaft doing the same thing?

Don't remember off the top of my head, but yes you can do that too!
Not a pretty or cheap repair!

 

[knightgang]

Ok, now I am confused as to what I should do? I don't want to shear a pump shaft.


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[knightgang]

One critically important note:
You will burn up or blow a seal on the pump if you keep running it the way you, are as you are dead heading the pump.

Are you referring to running with the loader off, having those lines disconnected is deadheading the pump?

If so, then this is very temporary as I have the loader removed for the repair work with the radiator fan and having good access to pull and clean the radiator and such. As soon as all of that repair is complete, the loader goes back on.

So, the comment tooljunkie about breaking the pump shaft was from deadheading the pump, correct? That be the case, then I should put on the quick connect and turn the valve...

 

[North Idaho Wolfman]

Sorry not trying to confuse you!

To fix the dead head issue,
Either:
1: Cap or put a quick disconnect on the bottom port or line and then change the selector valve and confirm pump flow by making sure 3 point works.
OR
2: Connect the lower port or line with the port (quick disconnect) above it thus creating a loop (Do not turn the selector valve) and confirm pump flow by making sure 3 point works.

Either way will keep the pump from dead heading and causing damage.
Any length of time of use or running can cause damage to the hydraulic pump or system while it dead heading.

 

[North Idaho Wolfman]

Are you referring to running with the loader off, having those lines disconnected is deadheading the pump?

If so, then this is very temporary as I have the loader removed for the repair work with the radiator fan and having good access to pull and clean the radiator and such. As soon as all of that repair is complete, the loader goes back on.

Yes with the lines disconnected and the selector valve or lines not allowing fluid to flow (IE dead heading) you can cause damage to the pump, seals, or drive of the system, and it doesn't matter if it's "only run for a min or two".
If you have run it "dead headed", after you either relieve the dead head condition or replace the loader, watch the engine oil level, if it rises during future operation you have blown the pump seal, if loader or three point operation is either week or nonexistent then pump or drive damage has occurred.
If no issues then you dodged the bullet and don't do it in the future.

 

[rbargeron]

Here's a diagram of the hydraulic block in your photo. If a tractor is not fitted with a loader the in and out ports are plugged and the screw slot points toward the letter O. When a loader is installed the screw is turned so the slot points toward the letter C (it only turns a quarter turn) This closes the direct path to the 3-point and diverts it to the FEL control valve. To restore 3-point function the FEL's power beyond port is connected back to to the block's in port.

Note that when there's no loader the diverter valve screw slot should point toward O. If it's left pointing toward C it won't deadhead because the relief valve will open. But you'll know it's working extra hard pushing all the flow through the relief.

 

[knightgang]

Yes with the lines disconnected and the selector valve or lines not allowing fluid to flow (IE dead heading) you can cause damage to the pump, seals, or drive of the system, and it doesn't matter if it's "only run for a min or two".
If you have run it "dead headed", after you either relieve the dead head condition or replace the loader, watch the engine oil level, if it rises during future operation you have blown the pump seal, if loader or three point operation is either week or nonexistent then pump or drive damage has occurred.
If no issues then you dodged the bullet and don't do it in the future.

If I have blown the seals in the pump, I assume I can have the pump rebuilt. How difficult is it to remove and generally what is a rebuild charge? Or, is it something that I could rebuild,reseal myself?

I am hoping that has not happened. I will be getting a quick connect fitting today and installing so that I can get the fluid flow back and see if any damage has occurred.

Let's pray that I dodged a bullet. I only ran it long enough to move it about 50 feet from where I dropped the loader to where it is sitting to be worked on. Maybe I got lucky. Hope so anyway as I need this machine this weekend to do more bush hogging at our land.

 

[North Idaho Wolfman]

Chances are in your favor.
I wouldn't worry about it, if the engine oil level is good now then your probably fine as when the seal goes it out will fill the crank case with hydraulic fluid fairly quickly.
Just avoid use till it's changed back.

 

[knightgang]

Here's a diagram of the hydraulic block in your photo. If a tractor is not fitted with a loader the in and out ports are plugged and the screw slot points toward the letter O. When a loader is installed the screw is turned so the slot points toward the letter C (it only turns a quarter turn) This closes the direct path to the 3-point and diverts it to the FEL control valve. To restore 3-point function the FEL's power beyond port is connected back to to the block's in port.

Note that when there's no loader the diverter valve screw slot should point toward O. If it's left pointing toward C it won't deadhead because the relief valve will open. But you'll know it's working extra hard pushing all the flow through the relief.

Two comments:
1. Why are there two returns form the implement? Is it because one is the power beyond that allows flow beyond the implement valve to that hydraulic power can be obtained elsewhere (Assuming there were remote hydraulics, etc.)
2. So, if the relief valve is working correctly and left the screw control in the "C" position so that it did not pump fluid on the ground through the open "in" port, then there is no chance that the seals blew, just the relief valve opened up. I hope so, that would be really reassuring.

 

[knightgang]

Chances are in your favor.
I wouldn't worry about it, if the engine oil level is good now then your probably fine as when the seal goes it out will fill the crank case with hydraulic fluid fairly quickly.
Just avoid use till it's changed back.

Thanks. Have not cranked it since it got parked for teardown. Will have the quick connect on tonight and start reassembly with my temp fix fan. Hopefully it will be in the woods on Saturday.

 

[rbargeron]

Two comments:
1. Why are there two returns form the implement? Is it because one is the power beyond that allows flow beyond the implement valve to that hydraulic power can be obtained elsewhere (Assuming there were remote hydraulics, etc.)
2. So, if the relief valve is working correctly and left the screw control in the "C" position so that it did not pump fluid on the ground through the open "in" port, then there is no chance that the seals blew, just the relief valve opened up. I hope so, that would be really reassuring.

1. yes, one return is for exhaust back to the reservoir (trans case), the other is full-pressure to power something else - in this case the 3pt.

2. yes, the relief would lift and prevent damage. I have the same block on my L3250 and sometimes I take the loader off and forget to turn the screw. It's clear right away that it's pressurizing with no place to go so the relief is opening, but at significant pressure. Running that way very long will get you reported to the tractor-abuse hot line

 

[North Idaho Wolfman]

Like rbargeron said there is a pressure relief valve that is supposed to open and allow the pump to not dead head (be completely fluid blocked) but it only allows partial flow thus severely restricting the flow and thus "possibly" causing pump seal damage.
It all really depends on too many factors to say either definitively "yes it will cause damage" or "no it won't cause damage".
That's why I always say don't do it.

One line goes into the block (high pressure) and high pressure pass or Power beyond (PB), and return (tank).

 

[knightgang]

Got a new PB hose made and installed a Quick Connect, everything is good now...


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[billrigsby]

I read this thread with interest, Does any of this pertain to a Grey L1500?

Reason I ask is when I bought this gal a couple of months ago, previous owner
had the FEL off and the "in and out" lines connected together, and the brush hog on it.

I do not see any thing like the photo in the original post on mine?

Sorry but Newbie to tractors, and hope he did no damage!