Why does my RYOBI Air Compressor make a hissing sound?

Last update: 31/07/2023, 14:20

RA-C2550-G, RC40A-G, R18AC-0

That noise is normal and occurs each time the pump automatically turns off once the tank is full or is switched off via the compressor’s on/off switch.
The release of air is the pump unloading the built-up air in the system ready for the next time the compressor is switched on.
This won’t occur if at any time you switch off the pump at the wall outlet. Doing so can cause serious issues with the air compressor.
If you hear continuous hissing after the compressor has stopped, you may have an air leak in a hose or fittings. Check hoses for damage and make sure to use Teflon tape on fittings.