belly pump on Farmall "M"

[deerjack]

I hooked up live hydraulics on my M Farmall and it worked well for a while but now has developed a problem. It seems to build up back pressure thru the belly pump which I am still using for oil storage and the result of this is oil is being pushed up thru to dip stick tube. The system still works but oil is leaking out of the system. Any ideas would be greatly appreciated.