The high pressure lower body and wheel spray system is designed to wash all of the areas mentioned with a 20 horsepower 90 gallon per minute, stainless steel vertical pump, operating at 245 PSI. All of the flows are directed to the front of the bus until the front of the bus has passed a sensor which then switches flows to the lower body and wheel sprays via motorized ball valves. With the switching, flows decrease and pressures increase due to the change in system spray nozzles.