Vacuum Pump Repairs: Noises, Leaks and Amps

A well-maintained Vacuum Pump will last many years. Occasionally, issues do arise and your pump might need repair. And sometimes these issues are difficult to decipher without an expert there. But there are some initial steps you can take to troubleshoot a cranky vacuum pump. When analyzing pump problems, look for the 4 following things:

  • Noises
  • Leaks
  • Ultimate pressure
  • High amperage draw


NoisesNoises can come from things like fans rubbing on fan covers or motor couplings with broken rubber elements. These are considered ‘external’ in nature and can often be remedied without complete disassembly. If no external source of the noise can be found, the unit will need to be disassembled to find the source of the noise.


There are only 2 main places a Vacuum Pump Leakscan leak oil from which are the oil case gasket or the shaft seal. The shaft seal is far more common and far more susceptible to leaks and usually fails due to oil contamination. Some pumps have an ‘external’ shaft seal which can be changed without complete disassembly while others must be completely torn down to repair. Though rare, oil case gaskets can sometimes begin to leak oil over time. When they do, it is usually an easy Gasket Replacement to repair.

Ultimate Pressure

Most vacuum pumps can endure some noise or even an oil leak when pumping pressure begins to climb- that’s when it is service time! Reasons for a pump being unable to achieve acceptable ultimate vacuum levels can vary, but usually require the unit to be disassembled to find out what the issue is when there are no indicators that the external part of the machine is damaged. Prior to disassembly, we look for obvious external problems; such as a ballast valve left open, a loose intake connection, or low oil level.

High Amperage Draw

High Amperage DrawAs Vacuum Pumps Wear and/or get large amounts of internal contamination, a larger load is put on the electric motor. This will result in manifesting itself as a higher amperage reading. High amp-draw is usually a good clue of internal vacuum pump problems.

Vacuum Pump Repair