The applicator includes two elongated conveyor rollers arranged in parallel alignment and inclined from a sealant application station toward a tire unloading station. The rollers simultaneously rotate a series of tires in the same direction about a common axis in side-by-side engagement with one end tire adjacent the sealant application station and the other end tire adjacent the unloading station. A kicker assembly unloads the latter end tire, whereupon the rollers advance the remaining tires toward the unloading station while maintaining coaxial rotation thereof. A fresh tire then may be positioned at the application station and the application and advancement steps repeated. The applicator further includes a sealant applicator for effecting airless spray application of sealant to a tire, together with a control system for controlling the position of the spray applicator and causing sealant to be purged a predetermined time after no sealant application is made. The applicator is suited for usage in a system for producing self-healing tires.