under the air cleaner , held in place by a rubber doughnut and looking straight at you > it is an Alum. Cylinder with a two prong electrical connector that has two small "arms" connected to rubber lines (a good time to make sure there are no cracks in the rubber - it tends to dry with heat/time. if so, replace rubber).
Remove valve (remember position)and clean with brake or carb cleaner. You clean by spraying inside with cleaner and giving the valve a good shake around. repeat a couple times until no more dirty fluid is coming out the other end.
enjoy.