I have an hvac background and once worked for a plumbing companny for 7 years but I am unsure of the answer to this problem. My mother has a well for her house. The pump will short cycle many times before finally shutting off. The pressure is about 75 high and 45 low. Shutting on and off each time with the pressure switch. Would this be a bad foot valve, press. switch or tank? Any help is appreciated. Thank you