LA1153 front end loader goes up 4 feet and stops, not QC

[Cory.hensch]

I have a Kubota M7040S with a LA1153 front end loader on it. The boom will raise about 4 feet off of the ground and then stops. If I curl the bucket it will go ahead and continue to rise. I've taken loose all of the Quick Connects and reassembled, but I'll probably do it again this evening. I've also taken loose one one of the hydraulic lines from the piston that raises the boom. When I do this the bucket will also continue to rise. I have not checked the pump pressure but since the bucket will go all the way up with the curling action or with one of the hoses loose I don't feel like it is a pressure issue. I feel like it is a return to reservoir issue but I don't understand why it will go up three feet and stop. I haven't taken loose the return piping yet to see what happens if it just goes into a bucket. I downloaded the Work Shop Manual last night so I was just in the process of figuring that part out.

I already replaced the control valve and was able to get it to be able to be broken in the same way so I can eliminate that part. Just for giggles I replaced that part before I checked the quick connects. I'm learning a ton in this process.

Any help would be greatly appreciated.

 

[D2Cat]

You can get that kind of odd response from loader valve is lines have been switched and placed in wrong position.

 

[Cory.hensch]

You can get that kind of odd response from loader valve is lines have been switched and placed in wrong position.

The problem started before any work was done. I did replace the control valve and messed up the lines initially (who knew hydraulic fluid would remove sharpie). However they are back in their original position. Up and down, curl and uncurl are all functioning. It just will raise 3 or 4 and then stop unless I am doing the curl or uncurl while I'm raising it up.

 

[Dave_eng]

The problem started before any work was done. I did replace the control valve and messed up the lines initially (who knew hydraulic fluid would remove sharpie). However they are back in their original position. Up and down, curl and uncurl are all functioning. It just will raise 3 or 4 and then stop unless I am doing the curl or uncurl while I'm raising it up.

How many lines are on your loader valve..... 6 or 7?

You could have switched other lines than the lift and curl.

The WSM is no help with the loader. There is a separate WSM for the loader.

Send me your email address and I will get the FEL WSM to you.

What lead you to replace the loader valve..... most unusual.

Dave

 

[Roadworthy]

I had a Mitsubishi tractor with the FEL. It acted "funny" after I replaced a hydraulic line. I noticed a slight leak at the fitting. I tightened the fitting and the FEL was normal again - didn't even need to add fluid. This may not be your problem but it may be worth checking for leaks.

 

[Cory.hensch]

How many lines are on your loader valve..... 6 or 7?

You could have switched other lines than the lift and curl.

The WSM is no help with the loader. There is a separate WSM for the loader.

Send me your email address and I will get the FEL WSM to you.

What lead you to replace the loader valve..... most unusual.

Dave

I replaced the loader valve due to the issue described above and ignorance. I just thought the valve had washed out in some place and once the pressure got too high it would stop going up. I was in a hurry to unload a camper so I threw the part at it.

I'm pretty confident I have the lines all back in place since it is misbehaving in the same way as it was before I started trying to fix the not rising above 3 foot level.

You would be my hero if you sent it to cory.hensch@gmail.com

It is the Seven line valve YW236 is the original part number for the valve. It is replaced with the current equivalent. the Picture is attached. Also the in and out lines went right back where they were. It was the lines attached to the spools that the sharpie washed off of so I couldn't get them back in place.

My knew moto is I can screw anything up once!

 

[Cory.hensch]

The problem started after I tried to unload this camper (picture attached) out of the back of my truck with 8 foot pallet fork extensions. I foolishly didn't pump out the 20 gallons of water that sits up against the cab of the truck. So it was all the way at the end of the pallet forks. I was able to lift the camper a few inches but nothing more until I removed the water. Then it went up pretty easily. So I feel like I might have messed something up doing that lift. However it worked after I pumped out the water so I'm not sure what happened.

 

[nocash247]

Did you check your fluid level? If you only go up 4 feet and run out of fluid but curling back your bucket retracts those pistons introducing enough fluid to continue to raise the bucket. Just a thought.

 

[Dave_eng]

I replaced the loader valve due to the issue described above and ignorance. I just thought the valve had washed out in some place and once the pressure got too high it would stop going up. I was in a hurry to unload a camper so I threw the part at it.

I'm pretty confident I have the lines all back in place since it is misbehaving in the same way as it was before I started trying to fix the not rising above 3 foot level.

You would be my hero if you sent it to cory.hensch@gmail.com

It is the Seven line valve YW236 is the original part number for the valve. It is replaced with the current equivalent. the Picture is attached. Also the in and out lines went right back where they were. It was the lines attached to the spools that the sharpie washed off of so I couldn't get them back in place.

My knew moto is I can screw anything up once!

Cory
Forum management prefer emails not used in posts as it subjects the forum to more spam. Use private message instead.
I should have mentioned this to you in my offer.

When trying to lift something too heavy the loader relief valve protects your tractor. The danger arises after you release the joystick and now the hydraulic fluid is trapped in the system. Forks can then act like giant levers working against the system causing damage, usually to bucket cylinders but not only cylinders.

Dave

 

[ki4dog]

I had the same thought, then realized the actuators are probably double acting, so no change in fluid level. My uneducated guess would be binding or bypassing, but I really don't have a clue.

 

[Cory.hensch]

The problem was in the third function valve. I'm not sure what it is, but when I took the third function valve out of service the FEL works perfect. There are two paths for fluid to return one is through the T port that goes back to the transmission. This is the return path for when the bucket curls or uncurls. The primary path is through the PB port (Power Beyond). This port has flow unless you are actively raising or lowering the boom. This PB port is what goes to the third function valve. So I'll figure out the third function valve soon, but I'll be able to get the camper unloaded this weekend without fixing it. I thought everyone might like to know the solution.

 

[Cory.hensch]

Did you check your fluid level? If you only go up 4 feet and run out of fluid but curling back your bucket retracts those pistons introducing enough fluid to continue to raise the bucket. Just a thought.

Thanks for the thoughts. It was the first thing I did. If it doesn't start then does it have fuel. It ended up being the third function valve malfunctioning.

 

[Cory.hensch]

I thought everyone would enjoy my misery and pain. I CAUSED ALL OF MY TROUBLE! I burned up the electric switch on the third function valve back in the spring. I was using the auger and shaking dirt off of the auger by changing directions quickly on the electric switch. This caused the switch to fail. The original switch would return to neutral on its own. I ended up getting a switch off of amazon with the only difference being that you have to manually put the switch back into neutral. At some point I bumped the switch so it was holding the third function valve in either of the directions.

After I bypassed the third function valve to unload the camper I put it all back into service so I could figure out what the problem was. I though well maybe the quick connects on the other side are important so I removed cleaned and reinstalled. Then I was going to troubleshoot the electric signal from the switch. Low and behold immediately after actuating the switch everything just magically started working. $1400 for an unnecessary FEL control valve. 20 to 25 hours of my time over two weeks before Dave the son of our Savior himself sent me the FEL manuals that I needed to figure out the hydraulic oil flow path. But it is now fixed and evidently I'm a hydraulic oil/Front end loader professional now.

I still love my tractor but this relationship is starting to feel like work.

 

[200mph]

Thanks for posting the root cause.

It might have been painful, but at least it is fixed.