Air Compressor: Tank won't hold air
A defective check valve allows tank air to escape through the unloader; replace the check valve if this happens. Loose air tube fittings also allow air to escape the tank. Tighten loose air tube fittings to prevent air tank leaks. A leaky safety valve or leaky drain valve allows tank air to leak out. Replace the safety valve or drain valve if defective.
These repairs may help solve your Air Compressor problem:
Replace the air compressor check valve
The check valve prevents tank air from back flowing to the pump. A failed check valve will apply high air pressure to the head of the pump preventing the motor from restarting once the tank has filled. If the motor starts when the tank is empty of air but won't restart when the tank is full, replace the check valve.
Tighten air compressor air tube fittings
Inspect air tube fittings regularly. Firmly tighten any leaking air tube fittings.
Replace the air compressor safety valve
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 or pops open at normal operating pressure.
Replace the air compressor tank
Don't try to fix a leaking air compressor tank. Replace the tank if it leaks air.