Yes, and get all that coolant out of your transmission! It will destroy the clutches!! The rad. is the only place it can be coming from that i know of. Just drain and refill or have a shop do it. I do not recommend flushing the transmission at all!! With the lines off of the radiator, start the engine and let the fluid run into a pan while pouring fresh fluid back into the trans until fluid runs clean and clear of water. Keep a steady stream going back into the trans!! Like i stated, if not equipped, have this done.