or when the truck is moved between jobs as understood by those skilled in the art the distributor truck 14 contains a heater for the liquid sprayed the heater is vented through a pair of vent pipes 50 the vacuum hood 16 like the distributor bar 44 has a main portion 52 extending transversely across the width of the truck and a pair of side portions 54 pivotable between a vertical 34 stowed 34 position shown in full lines in fig2 and 3 and a horizontal operating condition shown in phantom lines at the right hand side of fig2 and 3 the structure of the vacuum hood 16 is illustrated in more detail in fig4 and 6 in which the side portions 54 are shown in the horizontal condition as seen most clearly in fig4 and 6 the side portions 54 are attached to the main portion 52 by hinges 56 and are sealed to the main portion by gaskets 58 fig6 to form a single air chamber in this condition the vacuum hood 16 is a horizontal flat box elongated in the transverse direction and having the primary opening 22 at its forward edge or face the primary opening 22 extends the full height and width of the combined vacuum hood taking the form of an essentially open mouth cut at an angle of substantially fifty degrees from the horizontal to.