LeakGuard Professional A/C Stop Leak

LeakGuard is an oil-based sealant and will not harden, crystallize, or clog the A/C system or recycle equipment, and is compatible with R-134a and R-12. LeakGuard seeks out oxygen and air flow at the point of the leak. It is then pushed through the leak by the pressure in the system, then congeals and forms a chemical weld at the leak point.