1- Check Vacuum Pressure.
Higher pressure increases noise emitting from pump. If pump vacuum pressure is below 1 Torr, Locate noise source on your vacuum pump
2- Locate area of noise, if from pump or motor side
A) Pump side
i) Intake or exhaust lines are restricted or clogged - check both inlet and exhaust have free path of flow through hoses. Do not restrict the exhaust path to atmosphere, as restricting exhaust will create back-pressure in pump and lead to seal failure, particularly shaft seal damage.
ii)Coupling or spider coupling damage causes a squealing sound Contact Us for parts or service.
iii) Slapping noise is typical for some pumps operating certain processes, if pump is achieving good ultimate pressure and may not indicate pump damage. Contact Us for a free evaluation.
B) Motor side
i) Compare the pump motor rating, printed on a label on the side of the motor and on the serial number tag, to the power source, to be sure they agree in voltage, phase, and frequency.