A common problem with older swimming pumps is water leaking from the bottom of the pump motor, this is caused by a warn shaft seal, you must replace the seal to stop the leak, if you not sure how to accomplish this, follow the manufactures pump seal replacement information.
One problem is if the pump has leaked for along time, the shaft may be damaged, then the motor will have to be replaced.
Motors typically last an average of 5 to 7 years before rebuilding or replacing, a screeching front bearing or rear bearing will be loud enough to warn you of problems.
If you have to replace the motor
Look at the nameplate on the side of the motor for reference
Replace with the same horsepower as the original motor
Replace with the same speed motor
Replace with the same voltage
Replace with the same frame type