For maximum effectiveness and longest element life, keep the windshield and wiper blades clean, as dirt, tree sap, and road tar can cause streaking, smearing, and blade deterioration. Wash the windshield with a commercial glass cleaner at least once a month and wipe off the rubber blades with a wet rag. Avoid moving wipers across the windshield by hand to prevent damage to the motor and drive mechanism. To inspect or replace wiper blade elements, set the wiper switch to LOW speed and the ignition switch to ACC, then turn the ignition switch to OFF when the blades are vertical. Examine the wiper blade elements and replace any that are cracked, broken, or worn, as replacement intervals vary with usage, typically limited to about one year due to ozone deterioration. If the wiper pattern is smeared or streaked, or if the blade chatters, replace the elements, ideally in pairs. Aftermarket blades may use different types of refills; for example, Anco blades have a release button for easy refill replacement, while some Trico refills require a small screwdriver to release the refill from the retaining tab. Other Trico refills have metal tabs that unlock by squeezing them together, allowing the rubber filler to be withdrawn and replaced. Polycarbonate refills feature a locking device for easy release and installation. For Tridon refills, remove the wiper blade and pull the backing strip while twisting to free the refill, ensuring to replace it with an identical type. Always follow the part manufacturer's instructions closely and ensure all frame jaws are engaged during installation to avoid scratching the glass.