Once the cause of the cracking is determined, we can devise a custom plan for repairing the asphalt. Before the repair process can begin, the asphalts surface must be correctly prepared. If sand, dirt and other debris are not removed from the cracks, the crack filling material cannot adhere properly. Pressurized air is often used to help remove moisture and vegetation from cracks and a steel brush is also used to help remove debris from the cracks. Asphalt crack repair can also begin with routing. This method uses motorized equipment, called a router, to create a reservoir that has a smooth surface. The routing makes the cracks a more consistent size and allows the crack filling material to contract and expand more evenly.