After removing a non-working pump motor assy I discovered a white residue substance (seems like dry dw soap??) on the outside of the motor itself plus on the pan. This is the second motor failure in six years.
First, what caused this problem?
and second, can the motor be cleaned up and reused?
If the motor is dead, it needs to be replaced. Now it could have failed because of a leak, try to find out if the motor itself was leaking, or was it coming from somewhere else leaking onto the motor causing it to fail. The white residue could be detergent, or calcium and lime deposits. Look around for any signs of leaking.