A system of treating installed railroad ties, comprising a conveyance vehicle configured to move along a railroad track, one or more drill carriages slidably attached to the conveyance vehicle to drill one or more holes at predetermined locations in the railroad ties, an air dispenser configured to deliver a blast of air proximate the one or more holes sufficient to remove debris from and around the one or more holes, a preservative dispenser configured to deliver a predetermined amount of preservative material into the one or more holes, and a plug dispenser configured to deliver a plugging material to the one or more holes to seal the preservative material in the one or more holes.