257B MTL Hydraulic Problem

[JTWAT]

This has happened twice while working machine loading dirt. When I lift a bucket of dirt and return the bucket control to the neutral position, the bucket begins to dump the material and I can hear a whining sound under seat. If I raise the bucket to stop the drop, it will raise up but drop again. After dropping bucket to ground and cycling the control, it will start working again. Any thoughts?

 

[Tazza]

What happens if you jiggle the pedal slightly? Does it stop moving? Just wondering if it could be that the return spring isn't holding neutral just right.
It could also be a load check is not seating correctly, even a relief valve. As you can hear something, fluid is by-passing.

 

[JTWAT]

What happens if you jiggle the pedal slightly? Does it stop moving? Just wondering if it could be that the return spring isn't holding neutral just right.
It could also be a load check is not seating correctly, even a relief valve. As you can hear something, fluid is by-passing.

Thats what I was thinking too. But since it has only happened 2 times, I guess I'll have to wait for it to get worse before I can track it down.

 

[knogen]

Does it have self level? The spool is self level valve sticks and dumps oil to sump That would be the noise you hear under seat. It is a black valve in engine compartment. On right side

 

[JTWAT]

Does it have self level? The spool is self level valve sticks and dumps oil to sump That would be the noise you hear under seat. It is a black valve in engine compartment. On right side

No, no self leveler.