C and R Racing Radiators 59-00001 Dike Stop Leak, 1 Pack Can prevent a DNF in the event of a radiator puncture, cracked cylinder head, or head gasket Problem After extensive research, C & R racing has found a stop leak that doesn't leave a residue C&R Stop Leak stays suspended in the water so that when the water is drained, all of the stop leak is drained with the water leaving no residue