Starting System / Charging System (H4SO): Generator: Inspection: Brush

1. Measure the length of each brush. Replace the brush if wear exceeds service limits. There is a service limit mark (A) on each brush.

   Brush length: 

   Standard 

   18.5 mm (0.728 in) 

   Service limit 

   5.0 mm (0.197 in) 

   Fig 1: Identifying Brush Length Dimension

   Courtesy of SUBARU OF AMERICA, INC.
2. Check that there is appropriate pressure on the brush spring.

Using a spring pressure indicator, push the brush into the brush holder until its tip protrudes 2 mm (0.08 in). Then measure the pressure of brush spring. If the pressure is 2.648 N (270 g, 9.52 oz) or less, replace the brush spring with a new part. 4.609 - 5.786 N (470 - 590 g, 16.58 - 20.810 oz) pressure is required on the new spring.

Fig 2: Checking Brush Spring For Proper Pressure

Courtesy of SUBARU OF AMERICA, INC.