Neighbor had 30 hours on a rebuilt Deere 4240 injection pump. Head on the pump seized up. Rotary pump - Rosa Master. Rebuilder will not stand behind rebuild. Rebuilt pump has been on the tractor about 9 months ($2500 was cost to rebuild). John Deere store has documented hours as to when the pump was repaired and put back on. First pump did not have a seized head - just a wear part. Anyway they are saying water or biodiesel caused the problem and want another $2200 to repair this one. He does have a 500 gallon diesel tank and is not using that much diesel yearly as everything has went into the CRP. Fuel company says they have not had any problems but will send a water test kit. First question - - does water settle out of diesel like it does in a 80-90 wt transmission oil or gasoline? I seem to think it does. Could he pull diesel off of the bottom of the tank and see if there is water there?? Diesel tank has an electric pump with a steel tube to near the bottom of the tank. He wants to make sure it is either the diesel or something else before he puts another pump on and fills up. Last question - - if there is water in the diesel fuel can you clean it up? If you can't clean it up who can use the diesel? Thanks.