Update your semi truck with improved vacuum pump performance, with the Masport 13-5/8" x 3" HXL400WV Vane Pack that ensures you're Ready for the Road Ahead™. To allow a pump to generate a vacuum, this replacement component works to create a pumping action alongside other vanes that trap and compress air. Engineered with top-tier materials to increase pump efficiency and performance. FleetPride is your First Click in Heavy Duty®.