We claim the ornamental design for a brake reservoir cover, as shown and described.
FIG. 1 is a perspective view of a brake reservoir cover.
FIG. 2 is a front view of the brake reservoir cover shown in FIG. 1.
FIG. 3 is a rear view of the brake reservoir cover shown in FIG. 1.
FIG. 4 is a right side view of the brake reservoir cover shown in FIG. 1.
FIG. 5 is a left side view of the brake reservoir cover shown in FIG. 1; and,
FIG. 6 is a top view of the brake reservoir cover shown in FIG. 1.
The broken line showing of the environment is for illustrative purposes only and forms no part of the claimed designs. The bottom view of the brake reservoir cover is not visible in its normal and intended use, and thus that view has been omitted.