The basic application of XS models employs a two-lobed fuel tank with one lobe incorporating one Fuel Level Sensor. Every sensor is provided with a float which is associated with a variable resistance wiper contact. To maintain equal quantities of fuel within both the lobes the left lobe incorporates a suction jet pump while the right lobe contains a compensating siphon pump. If the resistances of the Fuel Level Sensors are not approximately equal it will be needed to turn off the sensors, and to look at the fuel level in each lobe visually. Where the levels vary, the suction jet pump should be checked. Moreover, if the Ford is worked on for a change of a sensor or fuel pump, then it is advisable that the associated hose clamps, gaskets and O-rings as well be changed.