The Jumbomatic is a sequential block fitted to JUMBO filling arms: a single double-acting function is enough to operate it. The block successively operates the various hydraulic functions: pump change-over, lifting/lowering the arm, transport safety, valve and air intake control. An electrical switch also isolates the "pump change-over" function; the vacuum is created in the tank while the arm is still in the vertical position, which is very convenient if you are using the tanker without the JUMBO arm, or if you already want to create a vacuum when leaving the field without having to move the filling arm from its transport position.