Tractor Repair: massey ferguson, massey ferguson 255, suction screen

Question
i am working on a massey ferguson 255. the tractor has a laoader on it. the problem i am having is the 3-point arms, pto and loader stop working after the tractor has ran for a few moments. i hooked up a pressure gauge and it showed 3000 psi when the 3-point, etc. are working, pressure drops to zero and 3-point etc. stop working. i can shutoff the tractor and restart it and everything works as it should but only for a moment. i also noticed a change in noise when pressure drops it sounds as if the pump has completly stopped pumping. any ideas or suggestions would be greatly appreciated.

Answer
Sounds like you have a supply restriction. Trace the suction line and see if there is a suction screen in the housing. Probably plugged with a paper towel or brake lining from the transmission. If there is no suction restriction then you got a bad pump or relief valve. Going to have check flow of the pump after you check the screen.