Discovering transmission fluid in your radiator can be alarming. You can tell this because the transmission fluid will turn pink and float to the top of the coolant reservoir or radiator fill cap and may cause the engine to overheat. This guide provides a thorough walkthrough of the causes and corrective actions to address this issue. Keeping your vehicle's transmission system in top condition is crucial for its performance and longevity.
There is only one reason why transmission fluid might end up in your radiator, primarily due to cross-contamination within the cooling system caused by a leaking transmission cooler which is located inside the radiator.
Diagnosing this issue requires a systematic approach to ensure you accurately identify the cause of the transmission fluid leak.
Start by checking the transmission fluid level through the dipstick or level port on the side of the transmission case. If the level is low, and you cannot see an external fluid leak it could indicate a leak inside the radiator.
When the engine is cold only, open the radiator or coolant reservoir cap and look for a pink or milky color in your radiator fluid, which signifies the presence of transmission fluid.
Once you've diagnosed the problem, the next step is to fix it to prevent further damage to your engine and transmission.
Begin by draining the contaminated coolant from the radiator. Since you must replace the radiator anyway remove it and the engine thermostat. Then use a garden hose to help flush the engine's cooling system. This should be done carefully to prevent environmental pollution.
This must be done after the radiator repair is completed, the reason for this is after the engine has been shut off the cooling system still has pressure in it which can backfill the transmission with engine coolant via the leak inside the transmission cooler. This transmission fluid service can help prevent a failure due to the contamination of engine coolant.
Preventing cross-contamination can save you from costly repairs down the road. Here are some tips to keep in mind:
The mixture of radiator fluid and transmission fluid can lead to severe damage to both your engine and transmission. If you are not comfortable performing these repairs, it is highly recommended to seek professional assistance.