Checking Brake Fluid Level

WARNING: This page is about a different car, the 2008 Infiniti M45 and 2008 Infiniti M35. However, it is still accessible from the selected car via links, so may be relevant.

Make sure that a brake fluid level in reservoir tank is within the standard (between MAX and MIN lines).
Visually check around reservoir tank for fluid leakage.
If the level is excessively low, check brake system for leakage.
Release parking brake pedal and see if brake warning lamp goes off. If not, check brake system for fluid leakage.

Fig 1: Checking Brake Fluid Level
Courtesy of NISSAN MOTOR CO., U.S.A.