Why Did the Coolant Change from Green to Brown?

[StBradley]

The reasons for the coolant changing from green to brown are: 1. The coolant has reached the replacement mileage or time limit; 2. When replacing the new coolant, the old coolant in the vehicle was not completely drained, causing a chemical reaction when mixed with the new coolant. The steps to replace the coolant are: 1. Unscrew the radiator cap to drain the coolant; 2. Run the engine at idle and inject clean water until the radiator discharges clean water; 3. Close the water valve after the clean water has completely drained; 4. Add new coolant until the liquid level is between the max and min water level marks; 5. Close the cap and let the engine idle for two to three minutes. The functions of the coolant are: 1. To provide anti-freeze protection for the engine against low-temperature environments; 2. To offer efficient heat dissipation; 3. To prevent the coolant from freezing and cracking the radiator or damaging the engine cylinder block and cylinder head during cold winter parking.