Bench Testing: Brush

WARNING: This page is about a different car, the 2004 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.

Measure the length of each brush. See Fig 1. If wear exceeds the service limit, replace the brush. Each has the service limit mark (A) on it. See BRUSH SPECIFICATIONS table under GENERATOR SPECIFICATIONS.
Checking brush for proper pressure using a spring pressure indicator, push the brush into the brush holder until its tip protrudes .08" (2 mm). See Fig 2. Then measure the pressure of brush spring. See BRUSH SPECIFICATIONS table under GENERATOR SPECIFICATIONS.

Fig 1: Measuring Brush Length

Courtesy of SUBARU OF AMERICA, INC.

Fig 2: Checking Brush Spring Pressure

Courtesy of SUBARU OF AMERICA, INC.