Replace windshield wiper blades that are cracked or show discoloration. Streaked or unwiped areas on the windshield indicate blade replacement is needed. The blades should not make chattering noises; this may indicate the blades are due for replacement.
The National Highway Transportation Board recommends replacing windshield wiper blades on an annual basis, with replacements every six months being ideal. Before purchasing replacements, check the length of the blade designated within the vehicle’s owner's manual. Although you may opt to simply replace the rubber portion of the blade, most blades manufactured today require the entire blade to be replaced.
Be mindful that windshield wipers deteriorate from the sun; heat cracks the blades and renders them ineffective. Also, using windshield wipers to clear debris impacts blade longevity. For further assistance on the best time to replace a wiper blade, simply purchase blades with built-in wear indicators that reveal the condition on the blades.
There are three types of arm mounts that connect to blades. First, a hook slot connector may be the easiest mount to use. Bring the arm to a right angle, and push the flat tab that hooks to the wiper. Second, a pin-type arm utilizes the same concept as a hook slot except the pin must be pressed behind the blade. This most likely entails the use of a screwdriver. Third, a straight-end connector requires the use of a screwdriver; after releasing the notch or tab, the blade may then be removed.