The continuing development of new deformation schemes for material pressure forming resulted in the appearance of new technological process of Expansion Equal Channel Angular Extrusion (Exp-ECAE), which was proposed by Sepahi-Boroujeni and Fereshteh-Saniee in 2015. The present original research is a novel approach to an alternative hydrodynamic study of the Exp-ECAE deformation scheme with wide use of the numerical techniques of computational fluid dynamics (CFD). Additional mechanical degrees of freedom (DOFs) for Exp-ECAE die tooling equipment were first introduced by accounting for the dynamic effects of independent translational motion of the external movable walls of an Exp-ECAE angular domain. The proposed novel paper provides the possibility for original engineering-friendly visualisation of dead zone formation in the process of Exp-ECAE pressure forming. Multiple results of CFD-based numerical modelling show new promising ways for engineering minimisation of dead zone areas through alternative triggering of different DOFs of Exp-ECAE die tooling resulting in independent transport motion of the external walls of an Exp-ECAE angular domain. Abbreviation: SPD is Severe Plastic Deformation; ECAE is Equal Channel Angular Extrusion; Exp-ECAE is Expansion Equal Channel Angular Extrusion; CFD is computational fluid dynamics; DOF is degree of freedom.