* Soft or spongy brake pedal: This is a classic symptom. The pedal feels like it sinks to the floor or requires excessive travel before engaging the brakes. This indicates a loss of hydraulic pressure.
* Hard brake pedal: While less common with a failing master cylinder, a completely blocked port can result in a hard pedal that doesn't respond well.
* Brake pedal going to the floor: This is a serious symptom indicating a complete loss of brake pressure. This is a very dangerous situation requiring immediate attention – *do not drive the vehicle*.
* Inconsistent braking: The brakes might feel strong sometimes and weak other times. This suggests an intermittent leak or internal problem within the master cylinder.
* Brake fluid leaks: You might see brake fluid leaking from the master cylinder itself, or near it. Look carefully around the master cylinder and brake booster for any signs of fluid.
* Brake warning light illumination: While the light can illuminate for other reasons (low brake fluid, ABS problems), a failing master cylinder can trigger it.
* Pulling to one side during braking: This is less directly related to the master cylinder itself but could be indicative of a problem if there's internal leakage causing an imbalance in pressure between the front and rear brakes.
Important Note: If you suspect your master cylinder is failing, especially if you experience a soft or going-to-the-floor brake pedal, do not drive the vehicle. This is a serious safety hazard. Have it towed to a mechanic for immediate repair. Driving with a failing master cylinder puts you and others at significant risk.
