Common Companion air compressor parts that sometimes need replacement
- Air filter. Attached to the pump inlet, the air filter screens impurities from the incoming air.
- Connecting rod. The connecting rod connects the piston to the crankshaft or eccentric bearing to move the piston up and down in the cylinder.
- Cylinder head. Fixed above the valve plate, the cylinder head houses the air inlet and discharge ports.
- Motor. The motor spins the crankshaft which drives the piston up and down in the cylinder to compress air.
What to do when your Companion air compressor tank won't hold air
The air tank will rust and eventually leak air if you don't drain condensate water from the tank through the tank drain valve regularly. Replace the air tank if you see rust on the bottom of the air tank. Loose air tube fittings will allow air to leak out of the tank, so tighten all air tube fittings to prevent air tank leaks. A failed check valve will allow tank air to escape through the unloader when the pump stops running. Replace the air compressor check valve if air leaks out the unloader when the pump motor stops. A leaky safety valve or leaky drain valve can also allow tank air to escape. Replace the leaky safety valve or drain valve.