A few years ago I had 2 that seized up on me at about 1/2 track but didnt hurt the motor.It woulda been 3 but on the 3rd pump when I put it together it would not turn,thats when I stopped.The gear and the rotor didnt have enough clearance and when it got hot it would seize up.Mellings didnt wanna fess up to their screw up,now I dont run any of their products.. good luck