What to do when your Powermate 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.
How to fix air leaks in your Powermate air compressor
Tighten air tube fittings where air escapes and replace any damaged air tubes. The check valve prevents tank air from back flowing to the pump and unloader. If air leaks out the unloader when the pump stops, replace the check valve because the check valve leaks air back towards the unloader. 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. Replace the air compressor tank if it leaks air. Rebuild the air compressor pump if it leaks air through the pump head when the pump runs because a broken valve plate seal is allowing air to escape through the pump head.