Under What Circumstances Should Brake Fluid Be Replaced?

[DiCecilia]

Circumstances requiring brake fluid replacement: 1. When the brake fluid absorbs moisture or contains impurities, it should be promptly replaced or filtered; otherwise, it may lead to insufficient braking pressure and affect braking performance. 2. If the vehicle exhibits inconsistent braking force during normal operation, the brake fluid should be replaced immediately. Before replacement, clean the braking system with alcohol. 3. When the vehicle experiences braking deviation, conduct a comprehensive inspection of the braking system. If the wheel cylinder rubber cups are found to be excessively swollen, this indicates potential quality issues with the brake fluid. In this case, replace with higher-quality brake fluid and replace the rubber cups simultaneously. 4. Replace brake fluid every two years.

[RosalieMarie]

I always pay close attention to car maintenance, and brake fluid is definitely not something to be careless about. Generally, it should be considered for replacement after two or three years or around 40,000 to 50,000 kilometers. If you frequently drive on mountain roads or notice softer braking in rainy conditions, you should be even more vigilant. The other day, I tested it with a moisture detection pen, and the water content had exceeded 3%—that's about as dangerous as driving drunk. The most obvious sign was when pressing the brake pedal, it felt spongy, the travel distance increased, and there was a squeaking noise. I remember during one maintenance check, impurities were floating in the fluid reservoir, and the mechanic said that was proof the brake fluid had oxidized and deteriorated. Nowadays, if I smell a burnt odor while driving in hot weather, it’s definitely a danger signal from an overheated braking system. And if the brake fluid level drops abnormally after replacing brake pads or calipers, it’s likely due to aging and leaking brake lines.

[LeBrody]

My old buddy has been running for six years, and I just changed the brake fluid for the third time yesterday. This stuff expires just like milk—going over two years without a change is playing with your own safety. Especially in the humid rainy seasons down south, brake fluid absorbs moisture and deteriorates easily. I use a test strip to check the water content every year before summer hits. If you're driving on a slope and notice the braking force weakening after repeated presses, it's time for an immediate check. Last time during a repair, the mechanic found rust on the piston rings and blamed it on low-quality brake fluid. The most obvious sign is to check the reservoir—if the fluid looks cloudy and dark like coffee grounds, it's definitely no good. Once after driving through water, the brakes started squeaking, and a test revealed the water content was twice the limit—scared me straight into a cold sweat.

[MacCorey]

New cars require brake fluid replacement every two years after purchase, while older vehicles need it every 30,000 to 50,000 kilometers. I make it a habit to check before winter and summer, as extreme temperature fluctuations accelerate brake fluid degradation. The easiest method is using a moisture test pen - when the indicator changes from green to red, it's a warning sign. Pay attention to pedal feel during daily driving: it's normal to pump the brakes twice when starting a cold engine, but if the pedal becomes spongy after continuous use, be alert. Frequent abnormal drops in reservoir fluid level often indicate aging pipes or leaks. If you smell burning, stop immediately - this signals severely overheated brake fluid. During my last maintenance, when the tube was pulled out, the fluid looked like soy sauce with bubbles - such cases demand immediate replacement.