PURPOSE: To prevent many clutch discs from being broken due to pressed contact with one another by interlocking and connecting a clutch operation hydraulic pump for right travel to another clutch operation hydraulic pump for left travel in series, and connecting one of the pumps to an engine, regarding a work vehicle equipped with a hydraulic clutch for travel in right and left directions.

CONSTITUTION: This vehicle is equipped with a hydraulic pump PL as well as a hydraulic motor ML for travel in a left direction, and a hydraulic pump PR as well as a hydraulic motor MR for travel in a right direction. When the vehicle is made to travel straight forward, a hydraulically separated multiple disc clutch device 20 is kept in engaged state. On the other hand, the device 20 is kept in disengaged state for steering the vehicle in either a right direction or a left direction. Also, the hydraulic pumps PL and PR for travel in right and left directions, and a clutch operation hydraulic pump P1 are interlocked with and connected to one another in series and coaxially and, then, formed integrally. Furthermore, the input shaft 80 of the pump PL is interlocked with and connected to the output shaft 81 of an engine E via a power transmission belt 82. As a result, the operation of all of the pumps PL, PR and P1 is interrupted, when some trouble occurs in a power transmission mechanism, thereby preventing a friction disc from being broken.