My #4 broke at the base of the nipple on the I.P. side so I replaced it with a new one from the dealer it cost me $40 but they (shawn) gives me dealer price
the new ones have a differant taper before the top of the nipple it kinda bells out and looks like a better design than OEM
make sure you don't have to force or pull the hard line to meet the I.P (or the injector for that matter)
if you have to bend it some where a long the line so it meets up so be it that will take stress and tension off the end of the lines

make sure the nipple is not cock-eyed (we have all seen a cock-eyed nipple or two right!) on the delivery valves