A fuel system for a work vehicle having fewer points of leakage and a secure or virtually damage proof location for the filler tube of the fuel tank is provided. The fuel system includes an integrated fuel tank which includes a fuel tank and a filler tube integrated as one piece and a counterweight having a complementary portion with a hole of sufficient size to allow passage of the filler tube. The integrated tank and the counterweight are arranged to allow the filler tube to pass through and be surrounded by the complementary portion. The complementary portion may also have a door providing additional protection to the filler tube and a secure and stable stepping area for the operator of the work vehicle.