The HYdraulic TRansient ANalysis (HYTRAN) program has under gone extensive revisions that correct and enhance the program to meet the needs of those analyzing and/or designing aerospace hydraulic systems. Presented in this paper are a discussion of the revisions, a detailed explanation for the changes, and evidence from flight-test data that the improved HYTRAN program can meet the needs of the aerospace industry. The revisions affect all aspects of the HYTRAN program: steady-state analysis, transient analyses, hydraulic component models, and overall program improvements. The effects of these revisions on hydraulic analyses have been to 1) correct previous steady-state and transient solution errors, 2) reduce user handling time, 3) increase computational efficiency, and 4) improve HYTRAN's hydraulic component library. This updated version of HYTRAN is currently being used to model both interacting hydraulic systems on the GD/FW F-16 multi-role combat aircraft, an Advanced Hydraulic Test Stand (AHTS) system for testing 8000-PSI hydraulic components, and other advanced aircraft hydraulic systems.