What Are the Reasons for Brake Fluid Loss?

[DiBrianna]

Automotive brake fluid is the liquid used in hydraulic brake systems. The reasons for brake fluid loss and their solutions are as follows: 1. Reason one: Brake pad wear. Solution one: Regularly inspect the brake pads. Brake pads have a service life (in urban driving, the lifespan of brake pads is approximately 50,000 kilometers). They must be replaced when worn to a certain extent. 2. Reason two: Leakage somewhere in the brake fluid pipeline. Solution two: Promptly repair the brake fluid pipeline and regularly check the brake fluid level. Insufficient brake fluid can allow air to enter, making the brakes less responsive.

[VanCalvin]

I've been driving this car for several years and noticed the brake fluid level dropping mainly due to leaks in the system. Last time I parked, I saw small oil stains on the ground. After checking at the repair shop, it turned out the brake caliper's sealing ring had aged and was leaking. Another common reason is the brake fluid reservoir cap not being tightened properly, allowing vapor to evaporate and reducing the fluid level. Over time, the fluid also absorbs moisture from the air, causing its volume to decrease. However, the most dangerous issue is leakage. If the fluid level gets too low, the brake pedal may become soft or even fail, directly affecting safety. I recommend checking the fluid level monthly; as long as it's above the minimum line, it's fine. If you accidentally hit a rock and damage the brake lines, it can also cause leaks. Early detection can prevent major repairs. Usually, after parking, take a moment to look around the wheels for any stains and address any issues promptly.

[DiNora]

As someone who frequently maintains vehicles, I understand that the reduction in brake fluid is mostly caused by minor leaks in the braking system. Examples include wear on the master cylinder piston, loose oil pipe connections, or failed hub seals. Deterioration of the fluid quality can also lead to a slight reduction because brake fluid is hygroscopic—over time, it absorbs moisture, causing its density to decrease. I've noticed that if the vehicle has been driven long distances or heavily loaded, the fluid consumption might be slightly faster. Another point is that after replacing brake pads, the demand for fluid compensation increases, but the change is minimal. The key is to regularly check the fluid level and color using specialized tools, and replace the fluid if it appears cloudy. Safe driving relies on this, and it cannot be neglected. Developing a habit of checking brake components at a shop every quarter is cost-effective and helps prevent potential issues.

[StLaila]

I find that the most common cause of low brake fluid is leakage. Check for leaks at the connection points of the brake lines or damage to the caliper oil seals. During short trips, the fluid level remains relatively stable; however, during long-distance driving or in high temperatures, evaporation may accelerate. A loose reservoir cap can also lead to minor loss. Timely repairs are the best solution, as delays may cause additional component wear.