Why Does the Brake Pedal Become Soft After Replacing Brake Fluid?

1 Answers
VanTheo
07/30/25 12:49am
There are two main reasons: substandard brake fluid or air in the brake system. Substandard or poor-quality brake fluid used during replacement: Currently, the most common brake fluids on the market are synthetic DOT3 and DOT4. The primary difference between DOT3 and DOT4 lies in their dry and wet boiling points. If the boiling point of the brake fluid is too low, it can easily vaporize in the system, causing vapor lock, which may lead to delayed braking or even brake failure. Residual air in the brake system: This occurs when air is not completely bled from the brake lines during the replacement process. Replacing brake fluid requires strict adherence to the correct sequence and method. If this issue arises, it is recommended to take the vehicle to a repair shop to have the air bled from the system.
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