a pushbutton control system for raising and lowering the dump body of a dump vehicle . included are &# 34 ; up &# 34 ;, &# 34 ; hold &# 34 ; and &# 34 ; down / float &# 34 ; switches which are connected in circuit with &# 34 ; up &# 34 ;, &# 34 ; down &# 34 ; and &# 34 ; float &# 34 ; solenoid valves . these valves on energization direct pressurized air into the &# 34 ; up &# 34 ;, &# 34 ; down &# 34 ; and &# 34 ; float &# 34 ; chambers of two air cylinders included in an actuating mechanism for a hoist valve controlling the telescopic hoist cylinders of the vehicle . the dump body is raised upon depression of the &# 34 ; up &# 34 ; switch with the consequent opening of the &# 34 ; up &# 34 ; valve . the depression of the &# 34 ; down / float &# 34 ; switch , resulting in the opening of the &# 34 ; down &# 34 ; valve , causes the dump body to lower by the forced contraction of the hoist cylinders . upon subsequent release of the &# 34 ; down / float &# 34 ; switch the &# 34 ; float &# 34 ; valve opens to allow the dump body to lower under its own weight . the depression of the &# 34 ; hold &# 34 ; switch , with the consequent closure of all the solenoid valves , makes it possible to hold the dump body against movement in any desired position . pilot lamps are provided to indicate the operating conditions of the control system in response to the actuation of the switches .