What is the usage method of automotive brake fluid?
3 Answers
For different types of brake fluid, they should not be mixed together, as this will reduce the braking effectiveness of the vehicle; do not mix gasoline, diesel, or engine oil into the brake fluid. Below is relevant information about brake fluid: 1. Properties: Automotive brake fluid is the liquid used in hydraulic braking systems. It must not undergo chemical reactions, be unaffected by high temperatures, and not cause corrosion, softening, or swelling to metals and rubber. The commonly used types are DOT3, DOT4, and DOT5. 2. Regular replacement: The volume of brake fluid changes with temperature variations, hence the brake fluid reservoir is equipped with a vent hole. The air drawn in through this hole may contain moisture or impurities, which can be absorbed or dissolved by the brake fluid, thereby lowering the boiling point of the moisture-containing brake fluid. When a vehicle brakes during prolonged driving, the temperature of the braking system rises, making the brake lines prone to vapor lock, where air is compressed, potentially leading to reduced braking force or brake failure. Therefore, for driving safety, brake fluid must be replaced regularly.
Every time I service my car, I check the brake fluid myself. The small container under the hood is the brake fluid reservoir. I open the cap to check that the fluid level is between the MIN and MAX marks. If it's low, I top it up with new fluid, using DOT 4 type—never substitute with other fluids as they can corrode brake components. The replacement cycle is usually every two years because the fluid absorbs moisture and weakens, affecting braking performance. Once, I delayed changing it, and the brakes felt spongy on a hill—scared me to death. Now, I change it regularly. Before changing, I make sure the car is stable and clean the area to prevent dirt from getting in. The bleeding process is crucial and should be done by a professional technician; doing it yourself might leave air trapped, causing brake failure. Safety first—don’t skimp on this. Regular checks help avoid major issues.
I pay special attention to brake fluid level checks during DIY car maintenance. Open the hood to observe the reservoir markings, and add the correct type (e.g., DOT 3 or DOT 4) if needed - never mix them as chemical reactions may damage system components. Regular replacement is recommended every 2 years or 30,000 km per the vehicle manual. When changing fluid, park on level ground and use special tools to bleed air, otherwise air ingress may cause spongy pedals. I always clean the work area to prevent debris contamination. Brake fluid is hygroscopic (absorbs moisture), lowering its boiling point which may cause vapor lock during hard braking. Timely replacement avoids risks - I recommend logging change dates for tracking. Professional shop replacement is more reliable to prevent errors.
