Why does the brake pedal feel harder than before?
2 Answers
The main reasons why the brake pedal feels harder than before are: failure of the brake booster pump resulting in loss of assistance; clogged vacuum tube; sticking of the master cylinder or wheel cylinder; clogged brake fluid line. Below are detailed explanations: Booster pump failure: The force applied to the brake pedal needs to be amplified by the brake booster pump. If the vacuum booster pump leaks or malfunctions, braking will become difficult. Clogged vacuum tube: A clogged engine vacuum tube leads to loss of brake assistance, making the brake pedal feel harder. Sticking master cylinder or wheel cylinder: If the master cylinder or wheel cylinder sticks, the entire braking system will fail to function properly, resulting in a hard brake pedal. Clogged brake fluid line: The primary cause of a clogged brake fluid line is aged or deteriorated brake fluid, which leads to reduced hydraulic pressure and a harder brake pedal.
The mechanic mentioned this issue during my last service. The most common reason for brakes becoming stiff is a problem with the vacuum booster pump. It's located in the engine compartment, looking like a black box, and helps reduce the effort needed to press the brakes. If it's leaking air or the connected hose is broken, pressing the brake pedal feels like stepping on a solid ball—extremely hard. Another possibility is that the brake pads have worn down to the metal backing, and the metal rubbing against the brake disc can also make the pedal feel stiff. If it's especially noticeable when the air conditioning is on, it's most likely an issue with the vacuum pump. This isn't a minor problem—I recommend getting it checked at a repair shop as soon as possible. Don't wait until the brakes really fail to regret it.
