Abstract: A system for adjusting a proper slump in a mixing drum of a mixing truck, the system includes a frame having an opening through which the mixing truck can pass; a camera mounted on the frame for viewing the mixing truck; a monitor for monitoring the camera, wherein the monitor is at a location remote from the mixing truck; a water pipe mounted on the frame for depositing water into the mixing truck; and a control panel for controlling the depositing of water into the truck, the control panel being adjacent the monitor. Optionally, the system may include a plurality of nozzles mounted on the frame and arranged for washing an exterior of the mixing truck. The system can be controlled from the remote location.