1 ton. 3/4 ton. 8500 & 8600 GVW. A Cap / lid / cover used to seal / close off the Reservoir fill opening of a Brake Master Cylinder Reservoir to contain Brake fluid. A holding container that supplies fluid for the Brake Master Cylinder. Exc.GVW 7,300 Lbs. Exc.Stability Control. Included with: Master Cylinder.