M-F 1428v loader bucket does not work

[1428 massey]

I have a 1422 loader on my tractor with a nimco hyd valve.Problem is bucket will roll one inch up and one inch down it sounds like fluid is by passing in valve and loads engine.checked cables they are ok.It started all the sudden when it happend no warning.Any input or diagrams would be Gratefulley appreacheated.

 

[1428 massey]

Thanks for the info folks.