l3400 3 point problem

[Greg4ea]

I'm having problems with my 3 point hitch picking up substantial weight after it was recently fully serviced, all filters changed, greased, engine oil changed, hydraulic filter changed and fluid checked. The front end loader works fine and has no problem picking up weight. I have a hay fork installed on the 3 point and recently went to move some 4x6 hay bales which I've always done with no problem. The only way the 3 point will raise with a bale on it is if raise the front end loader simultaneously while raising the 3 point.
Hydraulic fluid level is fine.

 

[TheOldHokie]

I'm having problems with my 3 point hitch picking up substantial weight after it was recently fully serviced, all filters changed, greased, engine oil changed, hydraulic filter changed and fluid checked. The front end loader works fine and has no problem picking up weight. I have a hay fork installed on the 3 point and recently went to move some 4x6 hay bales which I've always done with no problem. The only way the 3 point will raise with a bale on it is if raise the front end loader simultaneously while raising the 3 point.
Hydraulic fluid level is fine.

Something in the loader valve/circuit is blocking or diverting oil flow to the 3pt. Reconnect any hoses recently?

Dan

 

[Russell King]

Is there any diverter valve on your tractor that may have gotten turned to the wrong direction?

 

[TheOldHokie]

Is there any diverter valve on your tractor that may have gotten turned to the wrong direction?

The 3pt functions when the loader is being raised. In other words the loader is getting power from the tractor but the 3pt only gets power from the loader when the boom spool is shifted.

Q: Whats special about the boom spool?
A: Exhaust oul from the loader lift cylinders goes out the power beyond connection to the 3pt.

I will bet operating the bucket does not get the same result as the boom.....

Dan

 

[lugbolt]

I assembled a LOT of those.

L3400/LA463, even the newer LA525 loaders-the system is the same design.

If you swap the power beyond and return hoses on the hydraulic block OR the loader valve, you will get exactly what you describe, and for exactly the reasons stated above.

Is it possible that the loader hoses have been removed or swapped for some reason?

The two hoses that were frequently swapped at the hydraulic block on the tractor (below the right side floorboard) both had the same ends on them, so easy to screw them up. The other hose has a different end.

 

[TheOldHokie]

I assembled a LOT of those.

L3400/LA463, even the newer LA525 loaders-the system is the same design.

If you swap the power beyond and return hoses on the hydraulic block OR the loader valve, you will get exactly what you describe, and for exactly the reasons stated above.

Is it possible that the loader hoses have been removed or swapped for some reason?

The two hoses that were frequently swapped at the hydraulic block on the tractor (below the right side floorboard) both had the same ends on them, so easy to screw them up. The other hose has a different end.

What you are describing is "conventional" valve behavior. I could not find a WSM and I cannot speak for the older LA463. It may well behave that way. If so the curl function should also cause the 3pt to lift.

But the valve on the LA525/LA765 is not conventional and would not behave like that if PB and tank return are reversed. The LA525 sends boom exhaust oil to the power beyond port not tank. Operating the loader lift would send all oil to tank bypassing the 3pt entirely. Hence my earlier comments.

Dan

 

[Greg4ea]

Something in the loader valve/circuit is blocking or diverting oil flow to the 3pt. Reconnect any hoses recently?

Dan

I didn't and they don't appear to have been switched but I will definitely check them.

 

[Greg4ea]

Is there any diverter valve on your tractor that may have gotten turned to the wrong direction?

The only valve I know of is the needle valve beneath the seat to adjust the drop speed for the 3 point

 

[Greg4ea]

The 3pt functions when the loader is being raised. In other words the loader is getting power from the tractor but the 3pt only gets power from the loader when the boom spool is shifted.

Q: Whats special about the boom spool?
A: Exhaust oul from the loader lift cylinders goes out the power beyond connection to the 3pt.

I will bet operating the bucket does not get the same result as the boom.....

Dan

You are correct operating the bucket has no effect on the 3 point

 

[Greg4ea]

I assembled a LOT of those.

L3400/LA463, even the newer LA525 loaders-the system is the same design.

If you swap the power beyond and return hoses on the hydraulic block OR the loader valve, you will get exactly what you describe, and for exactly the reasons stated above.

Is it possible that the loader hoses have been removed or swapped for some reason?

The two hoses that were frequently swapped at the hydraulic block on the tractor (below the right side floorboard) both had the same ends on them, so easy to screw them up. The other hose has a different end.

I'll check that thank you.

 

[TheOldHokie]

You are correct operating the bucket has no effect on the 3 point

Do you have the WSM for the loader? Knowing exactly how rhe boom circuit works would be helpful in diagnosing the problem. Based on your testing it appears to he the same as the valve on the LA525. Assuming it is I am still having trouble visualizing how PB could be blocked in this fashion. Are there any hydraulic valces other than the loader on the tractor? Third function, rear remotes, etc?

Are you familiar with the hose connections at the hydraulic outlet block? Assuming no other valves in the circuif if you disconnect the loader valve tank return hose at the outlet block and start the tractor there should be no flow coming out of that hose. If there is an oil flow coming out that line something is FUBARed inside the valve.

Dan

 

[HCM]

I'm having problems with my 3 point hitch picking up substantial weight after it was recently fully serviced, all filters changed, greased, engine oil changed, hydraulic filter changed and fluid checked. The front end loader works fine and has no problem picking up weight. I have a hay fork installed on the 3 point and recently went to move some 4x6 hay bales which I've always done with no problem. The only way the 3 point will raise with a bale on it is if raise the front end loader simultaneously while raising the 3 point.
Hydraulic fluid level is fine.

I have the same issue with my 3 Point Hitch. With a load on it it will not pick up. With no attachment it does. The main difference in this thread is I do not have a FEL it is just a tractor. Any suggestions?