I am sure no one can answer this question but here it goes.
I hae a webtrol well pump motor that ran constantly. I replaced the rusted out capacitor and now it run only when the demand for water requires it to run and then it shuts off like it should when the pressure in the tank is 50 PSI. The question is can a Capacitor cause a motor to run constantly??

Art

Not Usually, pressure or timers are something that can.
Start and Run Capacitors are used?

Not Usually, pressure or timers are something that can.
Start and Run Capacitors are used?

Thanks for your reply. I found out that I do not have any pressure in my tank. I drained the tank completely and now trying to find out what PSI I should add before replenishing the tank with water. I found out that I have a leaky air valve so replacing and starting a nes.

Art

Why did you not have air in the tank? How did you know that you did not have air in the tank? Assuming you have a bladder tank with air valve on top and you pressed the needle valve and got water out instead of air you have a ruptured bladder. Replace tank.
A bladder tank should be pressurized to 2 pounds less than the cut on pressure of the pressure switch.