This lower initial pedal position allows for the release of any trapped air in the brake system, ensuring efficient and safe braking.
As you drive, the trapped air will rise to the highest points in the system and be released, causing the brake pedal to gradually regain its normal firmness over time.
Here's why this happens:
1. Brake Fluid Expansion:
When old, contaminated brake fluid is replaced with fresh brake fluid, it can absorb some moisture and tiny air bubbles present in the system. As the new brake fluid circulates, it expands slightly due to the dissolved moisture and air, leading to a reduced fluid level in the brake fluid reservoir.
2. Air in the System:
During the brake fluid flush procedure, there's a chance for air to enter the system, especially if the process isn't performed correctly. This air can become trapped in various parts of the brake lines and calipers, causing a spongy or low brake pedal feel.
3. Compression of Fluids:
Another factor is the compressibility of brake fluid, especially in the presence of air bubbles. When air is in the system, it can compress slightly under pressure, leading to a lower brake pedal position.
Will they adjust on their own?:
In most cases, the brake pedal should self-adjust and regain its normal firmness as you continue to drive. The trapped air will gradually rise to the brake fluid reservoir and be eliminated through the bleeder screws.
However, if you notice that the brake pedal remains excessively low or spongy after driving for a significant distance (a few hundred miles or kilometers), it's recommended to have the brake system inspected and re-bled by a qualified mechanic to ensure proper operation.
