A pneumatic distribution system to distribute a granular product to an agricultural implement includes a first pressure sensor, a second pressure sensor, a valve, and a controller. The first pressure sensor is fluidly coupled to a granular product storage tank and outputs a first signal indicative of a first static pressure in the storage tank. The second pressure sensor is fluidly coupled to a primary line that pneumatically delivers the granular product to the agricultural implement by guiding an air stream from a first section with a larger cross-sectional area to a second section with a smaller cross-sectional area. The second pressure sensor outputs a signal indicative of the static pressure in the second section of the primary line. The valve is fluidly coupled between the storage tank and the primary line and selectively enables the air stream to flow from the primary line to the storage tank. The controller, which is communicatively coupled to both pressure sensors and the valve, instructs the valve to enable the air stream to flow from the primary line to the storage tank until the first static pressure is greater than the second static pressure by a threshold amount.