1. Road film builds up on the wiper blades over time, reducing their effectiveness, so the wiper blades should be washed regularly in a mild cleaning solution.
2. Wiper blade assemblies should be inspected regularly. If the inspection reveals the presence of hardening or cracks on the rubber of the brushes, replace them. If nothing out of the ordinary is found on inspection, wet the windshield, turn on the wipers, let them run for a while, and turn them off. Uneven brush marks on the glass or streaks on clean glass indicate that the brushes should be replaced.
3. If the brushes do not clean the windshield well enough, then wax particles may have fallen on the glass when the car was washed automatically. These particles can be removed by adding a detergent to the washer fluid that has the property of dissolving wax.
4. If necessary, adjust the direction of the jet from the washer nozzle by turning the nozzle with a needle.