[tomtom72]

besides not filling the bladders my passenger seat pump was doing something similar, started out strong but would slow way down as it ran, not stopping completely though.

Anyway, when I took it apart I found that the rubber torn in several places and it was winding up around the motor shaft(?), where the screw holds the rubber to the drive. It's like a crank type of set up and one of the fragments was winding around the drive & stopping the motor.

The rubber dish washing trick over at the Reg site did the trick!