pump hums

[poolhelp101]

Just opening the pool and i primed the pump, but it just hums. same thing happened last year when i first opened the pool, the pump just hummed and i followed the advise of this forum in explaining to me how to get the impreller to start, which it did and the pump worked all last summer without any problems. now it's doing just as last year, the pump just hums.... my pump is 15 years old, it is a hayward superpump, self priming. i have an inground 21,000 gallons. my question is, should i do as you guys instructed last year with the impreller and try to get the pump running or do i just need to go ahead and buy a new pump since this one is 15 years old and it done this last year? please advise me as to what to do. i really need your help. thank you