- Brake Master Cylinder: If the master cylinder is faulty, it may not be able to generate enough hydraulic pressure to properly engage the brakes. This can result in a hard or spongy brake pedal.
- Brake Booster: The brake booster assists in amplifying the force applied to the brake pedal, making braking easier. If the booster is malfunctioning or has a vacuum leak, it may not be providing enough assistance, resulting in a hard brake pedal.
- Brake Calipers: Seized or malfunctioning brake calipers can prevent the brake pads from fully releasing, causing the brakes to drag and making them feel hard.
- Brake Lines: Rusted or obstructed brake lines can restrict the flow of brake fluid, leading to increased brake pedal pressure.
- Brake Pads: Worn-out brake pads can reduce braking effectiveness and make the brakes feel hard or unresponsive.
- Air in the Brake Lines: Air in the brake lines can cause a spongy or hard brake pedal.
Solution:
Diagnosing the exact cause of hard brakes on your Lexus SC400 requires a proper inspection and testing by a qualified mechanic. It is not recommended to attempt brake repairs yourself unless you have the necessary expertise and tools.
