Charles,

I believe that the water pump on those Sears machines is a seperate,
small, electric motor. I'd check to see if voltage is getting to the motor
during the "drain" cycle. I'd also check to see if the motor is working. If
you have power and the motor spins then look for a blockage in a hose.
Here's some advice on taking the machine apart.

http://www.applianceaid.com/

Dave M.