L3600 What is this for?

[Jammez]

Hi Folks

Looking for a bit of insight as to what this modification is on my L3600. There's a hose, with a cutoff tap, attached to the hydraulic fill point & teed off the back of the rear hydraulic connection block. Any ideas why this would have been done? Pics attached that might help.

Cheers

James

 

[Russell King]

That seems oddly done.

Usually a hose is run from a control valve tank return to the block OR to the sump fill if there is no block (or convenient sump port). Tank return is the only hose that should be teed together like shown in your picture.

So I am assuming that hose was added as some sort of tank return that probably isn’t needed. The valve at the end would be turned off so that the hydraulic fluid wouldn’t run out of the hose when you are adding fluid to the sump (since the hose has to be removed to add oil).

I see the valve is currently in the open position. Does any oil flow through it when the tractor is operating and any control valve being used?

I guess it could be some test port for checking pressure but the valve needs to be off for the hydraulics on the tractor to function.

I would recommend some research on the tractor hydraulic block to see what that hose position is. The hose could be removed along with that tee as far as I can tell.

I guess it could have been a return hose for something like a log splitter, but there are better ways to do that.

 

[North Idaho Wolfman]

It was done to run a single action cylinder.
Single action cylinders only need one power feed, but then need to bleed the pressure off on the other control lever action.

 

[Russell King]

It was done to run a single action cylinder.
Single action cylinders only need one power feed, but then need to bleed the pressure off on the other control lever action.

So why not have it run to a quick disconnect at the rear of the tractor?

I am assuming that you mean something like a dump trailer with single acting cylinder ( pressure lift and gravity down).

Perhaps that valve is closed, then connect an extension hose to the valve to reach the dump trailer and open the valve so the hydraulic fluid isn’t leaking out when making the implement changed? Maybe the previous owner didn’t like to use quick disconnect fittings or there is some type of screwed connector under that valve?

 

[TheOldHokie]

That seems oddly done.

Usually a hose is run from a control valve tank return to the block OR to the sump fill if there is no block (or convenient sump port). Tank return is the only hose that should be teed together like shown in your picture.

So I am assuming that hose was added as some sort of tank return that probably isn’t needed. The valve at the end would be turned off so that the hydraulic fluid wouldn’t run out of the hose when you are adding fluid to the sump (since the hose has to be removed to add oil).

I see the valve is currently in the open position. Does any oil flow through it when the tractor is operating and any control valve being used?

I guess it could be some test port for checking pressure but the valve needs to be off for the hydraulics on the tractor to function.

I would recommend some research on the tractor hydraulic block to see what that hose position is. The hose could be removed along with that tee as far as I can tell.

I guess it could have been a return hose for something like a log splitter, but there are better ways to do that.

Off the top of my head thar looks like the sump filler to me. That woulx be a return not a pressure port.

Dan

 

[North Idaho Wolfman]

So why not have it run to a quick disconnect at the rear of the tractor?

I am assuming that you mean something like a dump trailer with single acting cylinder ( pressure lift and gravity down).

Perhaps that valve is closed, then connect an extension hose to the valve to reach the dump trailer and open the valve so the hydraulic fluid isn’t leaking out when making the implement changed? Maybe the previous owner didn’t like to use quick disconnect fittings or there is some type of screwed connector under that valve?

If you notice it's connected on the other end to the valve.
It allows the cylinder to bleed off back to the sump.
Granted it's not the best way to do this.

 

[Russell King]

If you notice it's connected on the other end to the valve.
It allows the cylinder to bleed off back to the sump.
Granted it's not the best way to do this.

Are you saying the connection that is between the three point arms is a pressure output? I am confused since the teed end “should be” tank return. I assumed that the port between the arms was a sump fill port.

But I do recall seeing some posts where the tractor used the three point control valve to route pressure to a single acting cylinder.

So is the hose just stored between the out put port and the tank return?

 

[North Idaho Wolfman]

It's tee'd off of a remote valve output line, and the other end is a fill port (return).
The valve on the fill port connection allows the remote to work normally (closed) or as a single action remote (open).

 

[Jammez]

It was done to run a single action cylinder.
Single action cylinders only need one power feed, but then need to bleed the pressure off on the other control lever action.

Thanks for the responses so far folks. The only thing I connect to the rear hydraulics is small tipper trailer. It just has a single hose so would this be best to use on the connection that has this loop and open the valve? I can't say I really think about which of the 4 rear connections I use for it, seems to work fine on what ever I do use?