Should Coolant Be Replaced or Topped Up?

[McJoel]

Coolant should be topped up or replaced depending on the situation. If the coolant level is low and it's the same brand and model, you can directly top it up. If you want to use a different brand of coolant, you must first completely drain the original coolant before adding the new one. Generally, automotive coolant should be replaced every 2 years or 40,000 kilometers, and you can replace it directly when the time or mileage is reached. Here are some points to note when using coolant: 1. Try to use the same brand of coolant. Different brands of coolant may have different production formulas, and mixing them could lead to chemical reactions between various additives, rendering them ineffective. 2. Most coolants have a validity period of two years (some products may last longer), so make sure the product is within its validity period when topping up. 3. It must be replaced regularly, typically every two years or every 40,000 kilometers driven, with taxis requiring more frequent changes. When replacing, drain the old coolant completely, clean the cooling system thoroughly, and then add the new coolant.

[GenevieveDella]

Last time at the repair shop, I watched the mechanic check the coolant. He said there are three key points to look for. If the level is low, just top it up with the same color, but if it hasn't been changed for over two years or the mileage exceeds 60,000, the entire system must be flushed and refilled. If there are floating particles in the radiator or the color turns cloudy, replace it immediately, especially for older cars in northern regions where temperatures drop below -20°C. My experience is to test the pH level with test strips before winter each year. If the pH value is below 7.5, replace the coolant right away. Last winter, at -25°C, this method saved me from freezing risks. Never mix it with tap water when topping up, as scale can clog the engine's cooling channels, leading to much higher repair costs.

[SanCarter]

As a veteran driver with ten years of experience, the shelf life of antifreeze is what I value most. For new cars within five years, just regularly check the fluid level and top it up with the same specification if it's low. But after five years, rubber hoses start to age, and the corrosion inhibitors in the antifreeze are nearly depleted, so a complete replacement is necessary. Last week, I helped a neighbor check his seven-year-old car and found the antifreeze's freezing point had risen to -5°C. Continuing to use it could risk freezing and cracking the radiator. By the way, a reminder to southern car owners not to take it lightly—antifreeze also prevents overheating in summer. It's recommended to replace it every 50,000 kilometers, and remember to flush the system before adding new fluid to avoid contamination from old residue.

[DeEmmett]

Never mix different types of coolant! Last time I used the wrong specification and it cost me 8,000 yuan in repairs. Red, blue, and green coolants correspond to different chemical compositions, and mixing them can cause flocculent precipitates. If the coolant level is low, first check the reservoir's scale line—if it's below the MIN line, top it up with the same original brand. Pay special attention to the rate of coolant level drop; if it decreases by one centimeter in two weeks, check for leaks. For vehicles that haven't changed their coolant in three years, the reduced buffering capacity can lead to water pump corrosion. If you're handy, you can buy a freezing point tester—a small tool costing just a few dollars can save you from major engine repairs.