Weird backhoe removal 3 point setup and behavior

   / Weird backhoe removal 3 point setup and behavior #1  

rbstern

Platinum Member
Joined
May 23, 2011
Messages
755
Location
GA
Tractor
LS MT225E, Yanmar 2210
I took the LB1100 backhoe off my MT225 (XG3025) for the first time yesterday. When I got it dismounted and unhooked the two hydralic leads, I found myself with a strange situation: The two connectors on the tractor, which should be reconnected to form the "loop" for the hydrualic circuit both had female quick couplers. The backhoe had two male connectors. No way to loop the tractor lines without some type of adapter hose with two male ends. I went back to my original docs/bag from the dealer to make sure they hadn't included anything like that. No such luck.

Looked through the manuals. No guidance whatsoever. Watched a couple of Youtube videos on disconnecdting an LS backhoe, not model specific, but they always seem to loop the disconnected hydraulic lines.

Add more weirdness: With the loop not connected, my 3 point lift didn't work, but the FEL still worked. Hmmm. And the 3 point has no resistance: I can move it up and down by hand. Checked the 3 point lowering speed valve under the seat. Tried it all ways, left it in the middle.

Next, I swapped the male and female connectors on one set of the tractor/backhoe leads, so I would have male/female on the backhoe, and male/female on the tractor. After that I looped the tractor hydraulic lead. Same result: FEL works, 3 point does not.

I have a call into the dealer now, waiting for the mechanic to come on duty to talk it thru with him. Figured I would check here to see if anyone has an answer to this mystery.
 
   / Weird backhoe removal 3 point setup and behavior #2  
Don't run the tractor with the lines disconnected!

The reason why the loader works with the lines disconnected is because the fluid has no where to go and the relief valve on the loader valve is opening and dumping the excess pressure to the tank, therefore is not feeding the circuit beyond the loader valve.

Running like this for long period of time will cause the fluid to get really hot and damaging stuff like the pump.

Looks like the dealer messed up the quick disconnects for the backhoe. It's an easy fix or you can just get the dealer to fix that for you.
 
   / Weird backhoe removal 3 point setup and behavior
  • Thread Starter
#3  
Don't run the tractor with the lines disconnected!

The reason why the loader works with the lines disconnected is because the fluid has no where to go and the relief valve on the loader valve is opening and dumping the excess pressure to the tank, therefore is not feeding the circuit beyond the loader valve.

Running like this for long period of time will cause the fluid to get really hot and damaging stuff like the pump.

Looks like the dealer messed up the quick disconnects for the backhoe. It's an easy fix or you can just get the dealer to fix that for you.

I already did the connector swap and it did not change the result. Did not run the tractor for more than a minute or so with the lines disconnected.
 
   / Weird backhoe removal 3 point setup and behavior #4  
Yes but you need to find the right lines.

Because one of the lines will be the pressure line while the other will be the return/tank line.

Pressure line of the tractor, goes to pressure side on the backhoe valve. Tank line of the backhoe valve goes to tank line on the tractor.
 
   / Weird backhoe removal 3 point setup and behavior
  • Thread Starter
#5  
Yes but you need to find the right lines.

Because one of the lines will be the pressure line while the other will be the return/tank line.

Pressure line of the tractor, goes to pressure side on the backhoe valve. Tank line of the backhoe valve goes to tank line on the tractor.

There is only one way to hook it up, based on hose lengths.
 
   / Weird backhoe removal 3 point setup and behavior #6  
Are you using the rear remotes that came with the machine? There should be a lever to turn that remote on and off!
 
   / Weird backhoe removal 3 point setup and behavior #7  
Make sure all remote valves are centered.
The backhoe option added a third SCV to my tractor with a detented valve. When the backhoe is off the tractor and I forget to center that valve, it behaves as yours does, but it also makes a louder hydraulic howl than normal that reminds me to check the valves.
 
   / Weird backhoe removal 3 point setup and behavior #8  
Make sure all remote valves are centered.
The backhoe option added a third SCV to my tractor with a detented valve. When the backhoe is off the tractor and I forget to center that valve, it behaves as yours does, but it also makes a louder hydraulic howl than normal that reminds me to check the valves.

So on the LS tractors, the backhoe runs off a remote valve?

I thought it ran like the Kubota tractors, where you actually split the circuit and add the backhoe in the middle. Therefore my posts above.
 
   / Weird backhoe removal 3 point setup and behavior
  • Thread Starter
#9  
Are you using the rear remotes that came with the machine? There should be a lever to turn that remote on and off!

No rear remotes on my machine. One line from the under-step block that splits out hyrdaulics to the loader, and a tapped fitting on the left rear axle housing.
 
   / Weird backhoe removal 3 point setup and behavior
  • Thread Starter
#10  
Mystery solved. Either the factory or the dealer set this up differently than expected.

There's another quick disconnect on the other end of the line that feeds the backhoe, near the hydraulic block under the right footboard; it's attached to a line coming from the loader control valve assembly. There's an unused, male quick disconnect on the front of the block near the footboard. To change from backhoe to rear 3pt lift, I have to uncouple that line, and plug the line coming from the loader valve assembly to the unused male connector on the block.

Less convenient than looping the cable at the rear.

Nothing in the documentation, and no discussion of that issue when I took delivery of the tractor. In fact, I think I was told the opposite...that I should loop the feed at the back of the tractor.
 
 
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