What are the reasons for the brake pedal slowly losing pressure?
2 Answers
Brake pedal slowly losing pressure is related to the brake pump and master cylinder. Here are the specific reasons: Brake pump oil leakage or brake pedal spring failure: This requires checking whether the brake pump is leaking oil, then checking if the brake pedal spring has any issues, as well as inspecting whether the vacuum booster pump is damaged. All these conditions need to be thoroughly checked, identified, and resolved promptly. Master cylinder gas boost system failure or ineffective braking: If the brake pedal issue is solely due to the master cylinder's gas boost system failure, then the brake master cylinder needs to be replaced. If the braking is ineffective, find a mechanic to repair and adjust it.
This problem sounds quite concerning, and I guess you might be a new driver. The most common reason for the brake pedal slowly losing pressure when pressed is a leak in the brake system or air entering the lines. Simply put, it’s that spongy feeling when you press down without the usual firm feedback. It could be due to aging or cracked brake lines leaking fluid, or worn seals in the master cylinder causing internal leaks, gradually reducing hydraulic pressure. Sometimes, a stuck caliper preventing fluid flow can also cause this. Another common issue is a faulty vacuum booster affecting assist performance, making the pedal feel softer. Air in the lines requires bleeding; otherwise, pressure won’t stabilize. Remember, if the brakes lose pressure, don’t force driving—find a safe spot to stop and check the fluid level and for any leaks. Get it fixed at a repair shop promptly; replacing parts or fresh fluid usually solves it.
