How to Maintain an Oil-Lubricated Air Compressor


By Kim Hillegass, Sears PartsDirect

An air compressor is for more than just inflating tires–the energy contained in compressed air powers our most useful shop tools. Routine and regular maintenance protects the investment made in an air compressor and ensures it works efficiently and safely.

Before each use, check the compressor hoses for any signs of wear. Inspect the tank for weak spots, pinholes and rust; if you find damage, replace the tank. Also, check the belt for any wear or damage and replace if needed.

Start the compressor following the instructions in the owner's manual, and once it reaches shut-off pressure, test the safety valve. Wearing safety goggles, pull the valve ring to release pressure from the tank. The valve should close automatically. If it doesn’t close automatically, or if it doesn't release air when pulled, replace the valve.

Test for air leaks by checking that all connections on the hoses, transfer tubes or pipe connections are tight. If you find a leak, replace the faulty component. Don’t over tighten any connections.

After each use, shut off the compressor, unplug it and bleed all pressure from the system. Drain the tank by completely opening the drain valve at the bottom. Check the pump oil level following the instructions in the owner's manual and add oil as needed. Inspect and clean the intake vents, and check the air filter, replacing it if worn or clogged.

For every 100 hours of use–or as recommended in your owner's manual–change the pump oil. This is also a good time to check the belt tension and pulley alignment. Check and tighten the bolts on the air compressor, being careful not to over tighten.