how to crack fill
1 To fill smaller cracks you should use rubberized asphalt-emulsion crack filler. 2  Try to avoid getting any of the filler on unaffected areas as it can stain the driveway. 3  Apply the filler using a caulking gun if available. 4  If you donât have a caulking gun, the filler can be poured carefully into the crack. Now fill the crack with a cold process asphalt repair compound, such as blacktop. 2  Compact the compound with a tamper or a 4x4 wooden post. 3  After compacting, you may need to add more blacktop or compound material and repeat the tamping process to ensure a consistent, level driveway.