Stop Leak Products: AT-205, Lucas, Bardahl, Liqui Moly, Bar's Leak, Lubegard, Hapco, Blue Devil, XADO, Seal Lube, CD-2, Justice Brothers, Wynn's. Do "Stop Leak" Products Work? Do they cause damage to engine seals? Will they destroy an engine? Stop leak products compared for their ability to condition or soften hardened rubber engine components, impact on new rubber engine parts, ability to resist evaporation under normal engine operating conditions, and film strength or the ability to lubricate engine components. I buy all of the products and the supplies used to perform the testing to ensure an unbiased review. So, thank you for supporting the channel!