A-B1592353-AI TUBE-BREATHEROne New Aftermarket Replacement Breather Tube Fits Briggs and Stratton (Fits Briggs and Stratton) Small Engines This aftermarket replacement breather tube is part of the engine crankcase ventilation system. It allows trapped gases and pressure to escape the crankcase, preventing pressure buildup that can cause oil leaks and accelerated engine wear. Proper crankcase ventilation is essential for long engine life in lawn mowers, riding tractors,