What is the shelf life of brake fluid?
2 Answers
The replacement cycle for brake fluid is 2 years or 40,000 kilometers. Of course, the specific time should be determined according to the user manual, as the requirements may vary for each vehicle. However, the replacement cycle can only serve as a reference. The most direct method to determine whether it needs replacement is to check the moisture content in the brake fluid. If the measured moisture content exceeds 3%, it is recommended to replace it at an appropriate time. If it exceeds 5%, it must be replaced immediately. The method for replacing car brake fluid is as follows: 1. Open the car hood and locate the brake fluid reservoir. 2. Open the reservoir cap and use a syringe to extract all the brake fluid from the reservoir. 3. Add new brake fluid. The functions of brake fluid are: 1. Brake fluid has a very low freezing point, ensuring good fluidity at low temperatures. 2. Brake fluid has an extremely high boiling point, preventing vapor lock at high temperatures. 3. It does not cause corrosion to metals and rubber.
I've been driving for over 20 years and have encountered the brake fluid shelf life issue multiple times. Unopened brake fluid can last 3-5 years in storage without problems, depending on DOT type - DOT4 lasts longer than older types. But once opened, use it within a year as moisture absorption causes boiling point to drop sharply. In-car fluid is more critical - change every two years because the braking system absorbs water, reducing performance and braking power, which can cause accidents. I learned this the hard way when my brakes weakened on a downhill slope due to old fluid - nearly had an accident. Now I regularly test moisture content before maintenance - safety first. Developing this habit protects lives - don't skimp on this. Mechanics always emphasize this point.
