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Cooler Cleaner

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As with any transmission swap or rebuild, it's important to clean the transmission cooler lines before installing the new or rebuilt transmission. This removes the old transmission fluid as well as any dirt or metal particles. Even diluted with the cleaning solution, the fluid we removed was pitch-black and very burned, which gave us some insight into the general condition of the overworked 4L60E transmission. We continued to run cleaner through the system until it ran clear.