How to Maintain an Oil-Free Air Compressor


By Kim Hillegass, Sears PartsDirect

A great advantage of having an oil-free air compressor is the minimal amount of maintenance it requires­–the permanently lubed pump cylinder requires no further lubrication, which means no oil changes.

But an oil-free air compressor doesn't mean maintenance-free. You still must perform routine maintenance steps before each use for safe and efficient operation.

Check the Air Compressor Safety Valve

Follow the step below when checking the safety valve. Remember to wear safety glasses when performing the check.

  1. Plug the compressor in and run it until it reaches shut-off pressure.
  2. Pull out on the safety valve ring to release pressure from the tank.
  3. The valve should close automatically by itself. If the safety valve doesn't close automatically, or if it doesn't allow the release of air when you pull it out, replace the check valve.

Drain the Air Compressor Tank

The air drawn into the air tank on your compressor contains water vapor that condenses like rain inside the tank. Drain the tank of water after every use. The drain valve is located underneath the tank at the very bottom. Be sure you open the drain valve all the way, and allow the tank to drain completely.

Check the Air Compressor Air Filter

The location of the air filter varies by air compressor model, but most often it's located underneath the plastic housing around the head–check your owner's manual for the exact location of yours. If the air filter is made of paper or felt, replace it once it shows sign of dirt buildup or wear. If the air filter in your model is a foam filter, you should be able to clean it with soap. Let the filter dry completely before reinstalling. Replace the foam filter if it's damaged or worn.

Visually Inspect the Air Compressor

Inspect the hoses, valves and seals for cracks or signs of wear, and make sure fittings are secure. Check the power cord for damage or fraying and replace if you find any damage. Check the air tank for pinholes, rust or weak spots. If any damage is found, replace the tank–never try to repair, weld or drill into the tank.

If you need repair help or troubleshooting tips for your air compressor, check out our DIY Air Compressor Repair section.