- condition and degree of wear of the brushes. The brushes must move freely in the grooves of the brush holders;
- brushes fit to the collector and spring pressure on the brushes;
- appearance of the manifold. The manifold can only be cleaned with a clean rag soaked in gasoline or trichloroethylene. Sand the manifold only with fine-grained sandpaper. It is prohibited to use emery cloth for these purposes;
- condition of the self-lubricating bushings of the caps. Before installing new bushings, immerse them in engine oil (SAE 30/40) for at least 20 minutes;
- appearance of the anchor and stator. Make sure that their windings have no breaks or signs of burning.
(The original is located on the internet portal «BMWMan.ru»)