Abstract: A vehicle washing system uses a charge chamber gravity fed through a check valve from a wash fluid tank. A supply line connects the charge chamber to a compressed air supply. A discharge line connects the charge chamber to nozzles directed onto lights of the vehicle. First and second control valves are connected in series with the supply line and the discharge line respectively. The control valves are opened together so that a charge of compressed air from the compressed air supply pressurizes the charge chamber and discharges at least a portion of the prescribed quantity of wash fluid from the charge chamber through the nozzles. A pressure balancing passage balances pressure between the wash fluid tank and the charge chamber to allow the filling of the charge chamber under gravity through the check valve when the control valves are closed.