well pipes banging and tank hisses

Do I need a new tank which is a A.O. Smith V60 I got a new pump in my well and now I hear tank hissing and when pump shuts off the incoming supply pipe is moving and banging.I shut off well pump and drained the tank and put in air to 28PSI and is still doing it.switch is 30/50 when I check the needle valve the pressure is 55PSI in the tank thanks JIm

The only thing I can think would make a hissing noise would be water squirting into the air cavity through the rubber bladder. Those old AO Smith tanks didn't hold up very well, so it could be going bad.

bob...