I do understand that it’s compressed air, but what exactly is happening when it makes that sound? After driving one around for a few days (moving truck), it seems to be somewhat randomly occurring.
In: Physics
Every time you hit the brakes it uses some air pressure, say 5psi or more, and there could be minor random leaks. The air compressor has a kick in and kick out pressure regulator called an air governor. It’s usually set to kick off the compressor at 125-130psi. When it kicks off your air compressor (really it free wheels it but who cares), it activates the air dryer purge valve. It lets air pressure escape the dryer out the bottom for a few seconds, taking moisture with it, hopefully. You’re hearing the purge valve on the air dryer.
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