One of them is a sticking unloader valve. How does the unloader valve work? Briggs Stratton Pressure Washer Pump Unloader Kit 187879gs Washer Pump Pressure Washer Briggs Stratton The unloader valve is designed to respond to an increase in pressure or a change in water flow. How does a pressure washer unloader work . You should be able to adjust the valve on your washer to fit the project you are doing. How does a pressure washer unloader work? This is how to adjust an unloader valve on a pressure washer. In most pressure washer unloader valves, the valve is connected with whether or not you are holding down the trigger. How a pressure washer unloader valve works. A pressure washer unloader valve diverts the water flow through the bypass when the trigger on the gun is depressed. How does a pressure washer unloader valve work? The unloader valve is designed to respond to an increase in pressure or a change in water flow. A pressure washer unloader valve diverts the ...