The recommended fluid change interval is listed as “annually or every 500 hours, whichever comes first under heavy use.” “Heavy use” is not quantified (e.g., number of lock-to-lock turns per trip). More precise metrics would help commercial users.

Review of the Hydrive Admiral Series Manual

The Hydrive Admiral Series Manual is a technically robust document that will save you hours of head-scratching during installation and diagnostics—provided you have basic hydraulic literacy. Its flaws (lack of multimedia, dense jargon) are minor compared to the accuracy and completeness of the data inside.