L345DT FEL Hyd questions.

[bhaack]

Good afternoon all,

I am tasked with the repair of a L345DT. This has been a challenge for a while now, but the pertinate part for today is the loader and it's associated hydraulic system.

This machine has what I would call power beyond feeding the loader valve. This is an open center system, Power beyond pressure feeds the IN port of the valve, OUT port goes back to the other side of the power beyond valve. Loader mast and bucket hoses are attached to each spool as they should be.

Now, my buddy says the loader worked ok before any of this happened. I agree, I saw him use it.
He broke the motor, removed the loader, I split it and repaired the engine. It's all back together now and he wants some quick couplers between the loader valve and the loader. That's what I"m working on now.
I have it all hooked up again. The loader acts as if its trying to return under pressure. The 3pt hitch works as intended in all respects. This 345 has a single engine driven gear pump and the power steering works properly.

I didn't remove the loader, and my friend doesn't remember all of the connections to the loader valve, it's been a few years. There is a port on top of the transmission with a plugged fitting in it. He isn't sure but thinks there might have been a hose routed there from the valve. That would be a return line, but doesn't know where it came from on the valve. I'm not sure that it needs a separate return, my experience is in green ones, and they don't use a second return line. It's acting like its under pressure on the return side, but that doesn't make sense to me.

Anyway, is there any way one of you guys would happen to have a schematic for this setup handy?

I can take pics and provide any specific info needed to assist your diagnostics.

Thanks a million!
Brendon~

 

[007kubotaguy]

How many hoses are going to the loader valve? Six or seven. I would assume by your description that the loader is running off the tractor hydraulics. If so you are tapped in to the tractor hydraulics on the left side of the seat with an aluminum block with two hoses coming out of it. The front hose should be your supply or inlet on the loader valve. The rear port on the aluminum block will either be return or power beyond depending if you have six or seven hoses. If you have seven hoses the power beyond port goes to the rear of the aluminum adapter block. The return port which would be hose number 7 returns to the top of the transmission where you describe it as being plugged. If everything is plumbed correct and it still does not work properly try lowering your 3-point hitch. If the feedback rod is out of adjustment that can cause problems as well.

 

[North Idaho Wolfman]

Pictures cut out all the guessing!

 

[Russell King]

If you can post pictures that would help.

Ignoring the hoses from the loader to the cylinders for now…
There should be some line coming out of the hydraulic pump on the tractor. That line will need to go to the power in on the FEL valve. There is then a power beyond port that goes to the three point hitch.

The FEL valve should also have a tank return port that dumps directly to the sump of the tractor. That would probably be connected into the top of the transmission fill port but there is probably a port under the seat area also.

If there is a rectangular block in the line from the hydraulic pump that will be used to get the power from the pump and return it back to the tractor.

This thread gives a good diagram and description of the adapter block

B7100 Hydraulic block diverter (70060-00360 or 70070-00385)

Back in stock. CDN$40 plus actual shipping These are obsolete and no longer available. I have recently been contacted by a member asking if I will make him one of these after reading how I made mine. I know this comes up from time to time and would like to gauge the interest others might have...

www.orangetractortalks.com

I think I have some pictures of my L185 hydraulic system but it is only a rear remote valve and then the three point hitch. But that may be similar to the FEL valve configuration. But I think the power steering would be involved and have some type of priority valve that decides if the FEL can be used or if the steering is being used.

 

[bhaack]

How many hoses are going to the loader valve? Six or seven. I would assume by your description that the loader is running off the tractor hydraulics. If so you are tapped in to the tractor hydraulics on the left side of the seat with an aluminum block with two hoses coming out of it. The front hose should be your supply or inlet on the loader valve. The rear port on the aluminum block will either be return or power beyond depending if you have six or seven hoses. If you have seven hoses the power beyond port goes to the rear of the aluminum adapter block. The return port which would be hose number 7 returns to the top of the transmission where you describe it as being plugged. If everything is plumbed correct and it still does not work properly try lowering your 3-point hitch. If the feedback rod is out of adjustment that can cause problems as well.

There are 6 hoses. 4 to the loader, 2 run to the power beyond.
Left side of seat, aluminum block, hose fittings are on the top of the block.

I can provide pictures in the morning.

I would expect that power beyond simply inserts itself into the 3pt hydraulic circuit and flows oil normally when no hyd functions are being used. If the loader is moved, the 3pt wouldn't move, or only enough flow to do 1 thing at a time, What I don't get is if the 3pt goes down fine, doesn't that mean power beyond and the 3pt are basically a pressure free return? Wouldn't the loader valve just direct return oil to the power beyond, then flow through the normal 3pt return system? I guess my real question is, what is that sump return in the top of the transmission for? Why is it there and/or, do I need to use it?

Thank you very much for the assist!

 

[bhaack]

If you can post pictures that would help.

Ignoring the hoses from the loader to the cylinders for now…
There should be some line coming out of the hydraulic pump on the tractor. That line will need to go to the power in on the FEL valve. There is then a power beyond port that goes to the three point hitch.

The FEL valve should also have a tank return port that dumps directly to the sump of the tractor. That would probably be connected into the top of the transmission fill port but there is probably a port under the seat area also.

If there is a rectangular block in the line from the hydraulic pump that will be used to get the power from the pump and return it back to the tractor.

This thread gives a good diagram and description of the adapter block

B7100 Hydraulic block diverter (70060-00360 or 70070-00385)

Back in stock. CDN$40 plus actual shipping These are obsolete and no longer available. I have recently been contacted by a member asking if I will make him one of these after reading how I made mine. I know this comes up from time to time and would like to gauge the interest others might have...

www.orangetractortalks.com

I think I have some pictures of my L185 hydraulic system but it is only a rear remote valve and then the three point hitch. But that may be similar to the FEL valve configuration. But I think the power steering would be involved and have some type of priority valve that decides if the FEL can be used or if the steering is being used.

That block you reference does not exist on this L345DT.
I have a power beyond block on top of the 3pt valve and 2 lines running to the steering box for power steering. After that is the sump inlet, filter pump and pump pressure lines.

Thanks!!

 

[Russell King]

Here is a picture of the adapter block from my L185

The hard pipe on the left is pressure from the pump. The 90 degree elbow on the near side is still the pressure side and goes to the rear valve power in. The hose on the far side of the block (with a 90 degree hose end) is the power beyond from the rear valve. The hard pipe on the upper right goes to the three point hitch valve.

The hose that has two 45 degree fittings is the tank return from the rear valve. There was a plugged port in the tractor that was available for use.

The picture is from the brake side looking back towards the seat, The block is under the front of the tractor seat on my tractor.

Added on EDIT- sorry I was typing this when you posted so it is superfluous information

 

[bhaack]

 

[Russell King]

I am not sure what is going on but your friend might have mixed up the lines to the cylinders so you can try to trouble shoot that? You might also check that all of the quick disconnects are seated together well, if they are not seated well then the return flow is limited.

Where does the line on the side of the valve come from (or go to)?

Also, is this the problem you are describing: The loader lifts fine but it doesn’t lower properly. The bucket curl works fine and the three point lift work properly under all loader positions and movement.

Is there a float position on the valve for the loader and is it working correctly?

 

[bhaack]

I am not sure what is going on but your friend might have mixed up the lines to the cylinders so you can try to trouble shoot that? You might also check that all of the quick disconnects are seated together well, if they are not seated well then the return flow is limited.

Where does the line on the side of the valve come from (or go to)?

Also, is this the problem you are describing: The loader lifts fine but it doesn’t lower properly. The bucket curl works fine and the three point lift work properly under all loader positions and movement.

Is there a float position on the valve for the loader and is it working correctly?

I put that together because he wanted the quick disconnects, so I'm sure of the hose connections to the loader. I know I haven't cross connected the mast to the bucket and yes, I've done that before and it does make things wonky.
The line on the side of the valve, both of those run back to the power beyond plate attached under the seat on top of the 3pt valve. That's the source and return for the loader spool valve.
Those quick disconnect fittings are new from Bomgaars, so, I'll look at that closer. I expect them to work, but New doesn't always equal good.

The issue is basically that nothing really wants to move, extend or retract, it's giving me the appearance that the entire system has pressure on both sides of any function at the same time. That behavior is making me question the return side of the system. I know I have pressure, but it seems like I can't get oil out of the valve. There isn't any issue with pump loading or squalling relief valves while the loader valves are in neutral. This isn't making much sense yet.

 

[Russell King]

How experienced are you with the hydraulic system? Hopefully you know enough to be dangerous?

I an no expert but it is a fairly straightforward process to troubleshoot. Generally the open center system is just like a water hose that flows through a valve and onto the next valve and back to the sump. If one of the valves is actuated then the flow is (partially) diverted to whatever hose the valve is directing flow to. The cylinders are double acting so the flow of fluid in one side forces fluid out of the other side of the cylinder. That is normally back to the valve and to a tank return line. But since you don’t have a tank return line it should go back through the power beyond line.

So here is a suggestion for you to try. Mark both lines and connections on the lift cylinder so you can put them back where they were connected. Remove both lines from the lift cylinder. (you may want to plug or cover the cylinder ports to keep them closed). Put them both into a clean bucket. I assume the ends of these two lines are now open (no disconnect) so fluid will drip out and if the valve is actuated the fluid will be able to flow into the bucket.

Start the tractor and there should NOT be any fluid flowing out of the two lines into the bucket. Actuate the FEL valve to the lift position and fluid should flow from the correct hose and none from the other hose. Put the valve in the down position and the fluid should flow out of the other hose and none out of the original hose. If they act correctly then you know the valve is working correctly and the hoses are operating properly. Replace the hoses where they were installed if that was correct to begin with.

Don’t hold the valve very long and you may need to tie the hoses into the bucket if the jump or move when active. The fluid can be returned to the sump if you used a clean bucket or replace it later on.

You can check the curl cylinder in a similar manner.

Report back what you find out.

 

[PoTreeBoy]

When you say,

The loader acts as if its trying to return under pressure.

do you mean all the time, or just when you try to raise or roll the bucket?

Since your loader valve only has six connections, I don't think that case drain connection is used. Three possibilities,
1. The In and Out are reversed.
2. The 3pt feedback linkage is mis-afjusted. Try lowering the 3pt and see if the loader starts working.
3. You have some of the valve-to-cylinder hoses mixed up. This only applies if the problem only occurs when you try to actuate the loader.

 

[bhaack]

This is fixed. It wanted the 7th hose from the outlet to the transmission case port. For some reason, this time, the 3pt valve was restricted or 'under pressure' where as before it wasn't. I made a hose for the 2nd outlet port on the valve to the transmission case and this resolved the issue.