Here's why:
* Transmission Cooler Location: The transmission cooler is usually integrated within the radiator itself. While you've replaced the radiator, the problem might lie within the transmission cooler lines *connected* to the new radiator, or in a *separate* transmission cooler (some vehicles have both). A leak in these lines, a ruptured cooler, or a failed internal seal within the cooler would allow transmission fluid to mix with the coolant.
* Internal Cracks (Less Likely, But Possible): It's less likely, but a crack within the transmission case itself could also allow fluid to leak into the cooling system. This is a much more serious and expensive repair.
Troubleshooting Steps (This should be done by a mechanic):
1. Pressure Test the Cooling System: This will help pinpoint the exact location of the leak.
2. Inspect Transmission Cooler Lines: Carefully examine all the lines connecting the transmission to the cooler for cracks, leaks, or damage.
3. Inspect the Transmission Cooler (If Separate): If your Sebring has a separate transmission cooler, it needs thorough inspection for leaks.
4. Inspect the Transmission for Leaks: Check the transmission pan and surrounding areas for any signs of fluid leaks.
Important Note: Driving with transmission fluid mixed with coolant can severely damage both the transmission and the engine. This needs immediate professional attention to prevent further and potentially catastrophic damage. Don't attempt to drive the car until the problem is diagnosed and fixed.
