When air pressure in the system reaches the governor cut-out pressure, the governor directs compressed air to the unloader assembly. The unloader pistons move and hold the inlet valves open. With the inlet valves open, the compressor stroke cannot occur.

When air pressure in the system drops to the governor cut-in pressure, the governor exhausts the air from the unloader assembly. The unloader springs move the pistons back to their normal positions and allows the inlet valves to function normally.