A hydraulic device for a work vehicle includes a device body, a plug, and a filler insert. The device body includes a wall structure between surfaces defining internal passages including an access passage having a first diameter extending from an access opening in the device body to a hydraulic fluid passage extending through the wall structure from an entry opening in a first surface to an exit opening in a second surface to deliver hydraulic fluid through the wall structure. A plug is mounted to the device body to close the access opening. A filler insert is proximate the plug and has a shank having a circular cross-section of a second diameter that is less than the first diameter so as to be decoupled from the inner wall surface of the access passage. An annular space around the shank in the access passage allows the hydraulic fluid to encircle at least a part of the shank of the filler insert.