Clean the brush holder and the brush rip with a soft brush.
Do not use a steal brush for cleaning to avoid any damage.
Fig. 24 - 11 Brush holder with cover
24-30-36 Measuring the Length of Carbon Brushes
Measure the length of both carbon brushes with a calibre gauge.
Fig. 24 - 12 Brush length
Ensure to measure the length of the carbon brushes at the points shown in the picture above.
The evaluation criteria can be found in chapter 24-30-37 Evaluation Criteria.