Will coolant be lost when replacing the thermostat?
3 Answers
Coolant will be lost when replacing the thermostat. During the replacement process, the coolant must first be drained from the engine, which results in some loss. Additionally, the coolant may come into contact with impurities when removing the thermostat. Therefore, it is generally recommended to replace the coolant when changing the thermostat. Method for replacing coolant: Before completely replacing the coolant, conduct a thorough inspection to check for any leaks or cracks in the pipelines, with a particular focus on the five-way water pipe. The five-way pipe is named for its five connections to different parts of the vehicle, and the coolant flows through it to be distributed to various sections of the car. If there are any signs of coolant leakage in this area, replace the hose or reseal the connections as needed. Drain the old coolant and flush the liquid channels with clean water. Add water to the coolant reservoir and continue filling until clean water flows continuously through the engine cooling system. Then, idle the engine for 3 to 5 minutes to circulate the water. Initially, the water draining from the reservoir may appear slightly pink. Continue adding clean water until clear water flows out. Remember to disconnect the heater hose and drain the water from the heater core. After about an hour of draining, add the new coolant through the radiator hose to allow it to flow quickly into the radiator. Then, fill the coolant reservoir with another batch of coolant until it is nearly full. Start the engine and let it run for about 10 minutes. As some air is expelled from the cooling system, the coolant level will drop. Top it up to the "MAXT" mark on the reservoir.
When replacing the thermostat, it's inevitable to lose some coolant, which is a common occurrence in my long-term experience as an auto mechanic. The replacement process involves disassembling parts of the cooling system, and once the system is opened, fluid tends to leak out. The amount lost depends on the method of operation, typically resulting in a small portion being drained. After the loss, it's essential to replenish with new coolant; otherwise, the engine may overheat due to insufficient cooling, leading to severe damage. I always recommend keeping factory-spec coolant on hand. After topping up, it's necessary to bleed air bubbles and test the system pressure. While this task is straightforward, it's crucial for engine health. Take the opportunity to inspect hoses and the water pump to prevent leaks that could cause more trouble. Old coolant deteriorates over time, so replacing it is actually beneficial for the vehicle.
Replacing the thermostat inevitably leads to some coolant loss, which I've experienced several times. Last time my car's temperature was off, and upon inspection, the thermostat was stuck. During the process, fluid spilled all over the floor, forcing me to buy a new bottle to top it up. The loss was about a cup's worth—just prepare a bucket to catch the old fluid. Refilling after the loss is straightforward: locate the coolant reservoir and pour it in. However, ensure the antifreeze type matches; don't mix different colors or brands to avoid internal engine corrosion. Take this opportunity to check the system for any leaks, or the effort is wasted. After the fix, the temperature stabilized, making the minor hassle worthwhile.
