What should I do if the wiper scratches the glass with a loud noise?
The structure and working method of the wiper blade are very simple, but it is inevitable that there will be abnormal squeaking or banging noises, and sometimes the windshield will jump or shake. There are three reasons for this phenomenon, one is caused by the aging, deformation of the wiper strip itself, or the existence of foreign matter between it and the windshield; the other is the oil film on the windshield; The non-vertical surface of the glass causes the abnormal noise of friction with the windshield when the wiper strip rises or falls.
First check the first cause, first check whether there is foreign matter between the wiper strip and the windshield, then lift the wiper to the maintenance position, and check whether the rubber strip of the wiper strip has hardening, burrs, nicks, cracks or tears. If there are any, you need to replace the wiper blades. If there are only burrs, you can use 1000 grit sandpaper to lightly sand it twice and try again.
If the cause of the wiper blade is ruled out, you can perform a water spray test on the windshield glass. If it is found that there is no water on the glass, or the water will spread out quickly, it means that there is an oil film on the windshield glass, which causes the wiper blade to shake or make abnormal noises. In this case, you need to use a degreasing and glue remover to clean the windshield.
If neither of the two reasons is true, it means that the force of the wiper is different when it is working back and forth, which causes the wiper blade to produce abnormal noise. At this time, the wiper blade can be removed, a cardboard is placed on the windshield, and the wiper arm is gently placed. On the cardboard, check whether the lower plane of the wiper arm is in complete contact. If there is a certain angle, it means that the wiper arm is deformed. You can use a wrench to adjust the angle of the wiper arm. When adjusting, wrap the wiper arm with a thick towel to prevent it. Wrench damage can damage the paint on the wiper arms.