Official DeWalt air compressor parts

Troubleshooting common DeWalt air compressor problems

Your DeWaltair compressor is a handy DIY tool when it’s working correctly. When it’s not, Sears PartsDirect has the troubleshooting guidance to get your air compressor back in good working condition.

• Won't start with a full air tank. If your DeWalt air compressor won't restart after it fills the air tank, the check valve is likely stuck open. The check valve prevents tank air from back flowing to the pump. The stuck check valve causes high pump head pressure, preventing the compressor from restarting. Test the check valve by shutting off the compressor and pulling the ring on the safety valve to bleed the air from the air tank until it’s empty. Turn on the air compressor to fill the air tank. Bleed air out of the tank to reach the cut-in pressure so the pressure switch attempts to restart the motor to refill the air tank. If the air compressor won't start with air in the tank, replace the check valve.
• Won't start at all. Check the electrical outlet for power. Reset the house circuit breaker if the electrical outlet is dead. If the electrical outlet works, replace the pressure switch if it isn't sending current to the pump motor. Replace the pump motor if it doesn’t start when it gets current from the pressure switch.
• Won't build tank pressure. Shut the drain valve at the bottom of the tank if it's open. Check for air tank leaks and replace the tank if it's leaking. Tighten loose air tube fittings to prevent air leaks. The safety valve pops open to relieve excessive air pressure if the pressure switch fails to shut off the air compressor at the cut-out pressure setting. Replace the safety valve if it leaks air constantly. Worn pump seals prevent the pump from compressing air. If the pump won't compress air, rebuild the pump. The valve plate regulates airflow into and out of the pump cylinder to compress air, so replace the valve plate if damaged.

DeWalt air compressor parts that frequently need to be replaced

• Intake filter kit. The intake filter kit helps your compressor operate quietly and efficiently. Replace the intake filter if it’s damaged or it isn’t muffling compressor noise.
• Head gasket. The head gasket seals the pump assembly and allows for proper compression of the cylinder(s). If you notice your compressor is constantly kicking on and there is no air hose leak or air hiss, you may need to replace the head gasket.
• Valve plate assembly. The valve plate controls airflow through the pump of an air compressor. Excess wear on the compressor valve plate can cause air flow problems in the pump. If the tank isn't building air pressure as the pump runs, then you may need to replace the valve plate assembly.
• Pressure regulator. If the tank air supply is over pressurizing tools and you can’t adjust outlet air pressure by turning the regulator knob, you may need to replace the pressure regulator.