Here's why:
* Brake fluid pressure: Bleeding brakes relies on pressure created by pumping the brake pedal. The engine is not involved in this process.
* Potential damage: Running the engine while bleeding brakes can create additional pressure in the system, potentially forcing fluid back into the master cylinder and causing an overflow.
* Safety: Running the engine while working on the brake system can pose a safety risk, especially if the car is not properly secured.
However, there are a few exceptions:
* Power assist: If your vehicle has power brakes (most modern cars), you may need to start the engine briefly to engage the power assist function when initially bleeding the brakes.
* ABS systems: Some ABS systems may require the engine to be running for proper bleeding. Refer to your vehicle's repair manual for specific instructions.
Always consult your vehicle's owner's manual or a professional mechanic for the most accurate and safe procedure for bleeding brakes on your specific vehicle.
