Brake Line

WARNING: This page is about a different car, the 2013 Infiniti M56 and 2013 Infiniti M37. However, it is still accessible from the selected car via links, so may be relevant.

Check brake line (tubes and hoses) for cracks, deterioration or other damage. Replace any damaged parts.
Depress the brake pedal with a force of 490 N (50 kg, 110 lb) and hold down the pedal for approx. 5 seconds with the engine running. Check for any fluid leakage.
CAUTION: Retighten the applicable connection to the specified torque and repair any abnormal (damaged, worn or deformed) part if any brake fluid leakage is present.

Fig 1: Identifying Brake Fluid Leakage
Courtesy of NISSAN NORTH AMERICA, INC.