I wrote about this to another member. My pump also did not work and had to be primed. Because of age and/or lack of use this is common on self-priming pumps. The easiest and cheapest solution is to buy a new Pump Head (ShurFlo model 208
. I got mine from Amazon.com and it was around $50. This is the entire pump head. You will leave the motor portion installed and unscrew the black plastic pump head and disconnect the two red wires. This way, replacing the entire head ensures all new rubber diaphragms, check valves, and switch operations. It screws onto the old motor with three screws and then you are done.
Once replaced, I turned the switch for the power drain on and it immediately gave a strong gurgling noise. I had a two gallon bucket of water on hand to test it. I poured it all in at once and within seconds it was gone. If a self-priming pump is working properly it should be almost instantaneous. Good luck!