Is Brake Fluid Really Unnecessary to Replace?
2 Answers
Brake fluid must be replaced. When the braking system operates, it transmits energy through the brake fluid. Liquids generally do not deform easily and are not compressible, making them relatively stable in energy transmission. However, the working environment of brake fluid involves high temperatures, especially during continuous braking, where temperatures often exceed 100 degrees Celsius. This severely tests the quality of the brake fluid. Generally, brake fluid should be considered for replacement once its water content exceeds 3%, and it must not be used if the water content exceeds 5%. Most brake fluids are inherently corrosive, and this corrosiveness increases with higher water content. Long-term failure to replace brake fluid can damage the metal and rubber components of related parts, leading to a faster decline in braking performance. In most cases, brake fluid should be replaced every two years, though some high-quality brake fluids may last slightly longer.
I used to think brake fluid didn't need frequent changes, but after driving for over a decade, I realized how wrong I was! Once I nearly rear-ended someone on the highway because the brakes felt spongy. At the repair shop, the mechanic said the brake fluid had absorbed too much water, lowering its boiling point and causing bubbles when braking. This stuff is meant to transfer pressure—water contamination makes it ineffective. Long-term neglect can also corrode brake lines and pumps, costing thousands to replace. I recommend changing it every 2-3 years or by mileage, especially after rainy days—just test moisture content with a tester pen. Safety first—don't penny-pinch over small costs and risk big trouble. Now I get mine checked regularly.
