Bobcat 331 swing will not lock

[rockyhollowman]

Hello, just join today, having trouble with my 2007 331 Bobcat mini hoe, the swing will not stay in place when you let go of the joy stick. you can also move it around with your hand when in the netural position. Someone told me the bolts were broke in the circle, I have check all that and can't find anything broke. I also locked the pin in and turned it and it would pull the motor down. I'm pretty sure it a valve somewhere stuck but don't know where it fine it.
Any help or pics would be helpful

 

[laurencen]

if you rotate with the hydraulics and put the bucket against a obstruction does the motor still turn or stall out with continuous force trying to turn

 

[rockyhollowman]

It works ok just does not lock, someone told me there was a seal blowed in the swing motor, I just rebuilt it and still the same, with the boom up you can move it around by hand, something is not locking it when you are not in motion

 

[laurencen]

so when you swing with the machine it has force, like pushing the spoils back into the trench? was thinking possibly a shear pin somewhere maybe