Abstract: A pneumatic tire seater for seating a tubeless tire on a rim has an advanced rapid air release (RAR) valve mounted on a tank suitable for containing pressurized air. A nozzle is mounted on one end of the RAR valve, and the other end of the valve is in unconstrained pneumatic communication with the interior of the air tank. A piston is within a cylinder of the RAR valve. A control chamber behind the piston contains a compression spring. Control gas passageways provide constrained pneumatic communication between the control chamber and the air tank, passing control gas into the control chamber. In response to actuating a control mechanism, the air in the control chamber is vented out into the atmosphere causing the RAR valve to rapidly open, producing a blast of air of sufficient magnitude to seat a tire on a rim.