Road film can build up on the wiper blades and affect their efficiency, so they should be washed regularly with a mild detergent solution. The windshield wiper and blade assembly should be inspected periodically. Even if you don't use your wipers, the sun and elements will dry out the rubber portions, causing them to crack and break apart. If inspection reveals hardened or cracked rubber, replace the wiper blades. If inspection reveals nothing unusual, wet the windshield, turn the wipers on, allow them to cycle several times, then shut them off. An uneven wiper pattern across the glass or streaks over clean glass indicate that the blades should be replaced. The operation of the wiper mechanism can loosen the fasteners so they should be checked and tightened, as necessary, at the same time the wiper blades are checked. For wiper blade replacement, park the wiper blades in a convenient position to be worked on. To do this, run the wipers, then turn the ignition key to Off when the wiper blades reach the desired position. Lift the blade slightly from the windshield. Squeeze the retaining lever to release the blade, unhook the wiper arm from the blade and take the blade off. Do not press too hard on the spring lock or it will be distorted. Slide the new blade onto the wiper arm hook until the blade locks. Make sure the spring lock secures the blade to the pin. For wiper element replacement, insert a screwdriver blade between the wiper blade and element. Twist the screwdriver clockwise while pressing in and down to separate the element from the end retaining claw. Slide the element out of the remaining retaining claws. Starting at either end of the blade, slide a new element into the second retaining claw. Slide it through the other retaining claws until it reaches the end of the blade. Bend the element and slide it back into the claw at the end of the blade.