i recently purchased a ford 4500 tractor with backhoe attachment. i replaced all of the hydraulic hoses due to them being wore out. where they attach to the pump there is two rows i'm assuming fluid out and fluid in. some of the hoses screwed directly into the pump and some of the had a nipple that screwed into the pump and then the hoses screwed onto the nipples. some of the nipples when you shook them rattled which i assume is some kinda backflow or something. i think i got some mixed up because the arm moves a little and stops. i assume the backflow is sealing off the fluid. does anyone know whick hoses get the nipples with the backflow device.