Sea Foam® TransTune emphasizes that it doesn’t swell transmission seals or act as a stop leak. Why is this so important?
Use of a stop leak additive, while a convenient short-term fix for a leaky transmission, can end up doubling or tripling the transmission repair costs you eventually will have to face. As the stop leak additive is absorbed into the seals and o-rings within your transmission, it causes them to soften and expand, and this is what temporarily stops the leaks. However, the stop leak additive fundamentally alters the consistency and density of those seals and o-rings, changing them from a firm dense rubbery material into something resembling the consistency of a marshmallow. This changes the torque tolerances between metal components and allows for more movement and vibration between these parts. Eventually, mechanical vibration shreds the now-softened seals, causing a catastrophic failure of the seals. So, what started out as a simple issue involving a single leaking seal, now affects EVERY seal and o-ring in your entire transmission, requiring a total tear-down of the entire transmission
