The following information pertains to motor homes that utilize the Semi-Automatic Water Purge and Repriming Fuel Filtration system for diesel engines. Originally known as the Winn Fuel System, the component is located in the rear engine compartment and is green in color. The Racor Fuel System, which has recently acquired the Winn Fuel System is similar in design, but tan in color.

The repriming feature of the Winn System is designed to allow the RV operator or service technician the convenience of automatically priming the fuel system when the engine is off to eliminate excessively cranking the engine. To engage this automatic priming feature, turn off the engine and place the ignition key at the dash in the On position. At the control panel, located in the engine compartment, press the Air Purge button to activate an internal pump that forces unwanted air from the fuel system. Once engaged, the internal pump operates for approximately sixty seconds to draw fuel from the fuel tank, push it through the fuel water separator and the injection system to force trapped air into the tank return line. This feature will provide uninterrupted fuel flow to the engine on demand. The priming function can be reactivated several times if required.

Water is heavier than fuel and will collect at the bottom of the filter housing. Located in the bottom of the fuel filter is a sensor probe that will engage the Water in Fuel light at the dash when detecting water at the bottom of the fuel filter. If the Water in Fuel light illuminates, pull off the roadway as soon as it is safely possible. Turn off the engine and place the ignition key to the On position. Examine the fuel filter control panel located in the engine compartment at the rear of the coach to determine if the H2o light is illuminated. If so, press the H2o Purge button. The pump will cycle to evacuate excess water from the fuel and into the plastic bag or plastic bottle. Do not allow the tainted water to run directly onto the ground.

On occasion, and during driving rain, moisture may work its way into the wiring and trip the Water in Fuel light at the dash. In this case there is no water in the fuel filter, and once the wiring has dried, the warning light should go out.

The Winn and Racor Fuel Systems include a primary fuel filter used to collect large particles. Updated versions of this filter system comprise a clear plastic primary filter that provides clear viewing of what is going through the fuel tank. Routinely perform a visual inspection of this filter during maintenance. For added security, cover the filter using a section of heat tubing similar to the type used to wrap water pipes. This will help to protect the clear plastic primary filter from rocks and debris.

When changing the primary fuel filter, turn the thumbscrew located on top of the filter counterclockwise and remove the screw. Pull up the filter and remove it from the top of the housing. Two O-rings are installed on the plastic fuel filter - one on the top and one on the bottom. The new replacement filter may also include new O-rings. Prior to reinstalling the O-rings, lubricate the surfaces using fuel or Vaseline. When reinstalling the filter, use caution to avoid over-tightening the thumbscrew. Resetting the thumbscrew too tight can prevent a seal and create an air leak within the fuel system.

Keep the control panel clear of dirt and debris. Avoid high-pressure water flow from hitting the control panel and switches. Potential problems that may indicate the need to change the control panel include no power to the panel, steady illumination of lights other than the Green LED power light, continuous power even when the engine is engaged, and failure of the Air Purge and H2o purge buttons to operate. For assistance in replacing the attachable control panel , contact Racor Fuel Systems technical support at (800) 344-3286.