[AT] Problem

[Richard Fink Sr]

Hi every one i have a hydraulic problem on my back hoe Case 580B mid 70s. I 
was working it Wednesday digging out stumps. Lost all hydraulics instantly 
one swing fine went to dig next bucket half way in quit, Making a 
chattering noise thought pump drive stripped or to low on oil topped off 
same thing. Removed pump, drive is ok. thought maybe stuck pressure valve 
removed looks ok very tight space can't see in real good.  have pump in a 
shop to be pressure tested. it was full of oil and pushed when i removed 
turning by hand,????? any suggestions On a side note i replaced a boom 
cylinder on this tractor about 1 year ago. After i had a sort of wining 
noise under heavy hydraulic pressure. thanks
R Fink
PA