What Causes the Brakes to Become Harder After Turning on the Car Air Conditioning?
1 Answers
There are several reasons why the brakes become harder after turning on the car air conditioning: 1. Increased engine load: Normally, when pressing the brake pedal, the accelerator pedal is released. At this time, the engine speed remains relatively high due to the vehicle's inertia, while the throttle is nearly closed. As a result, the intake manifold vacuum reaches its maximum, providing the best braking performance. However, when the air conditioning is turned on, the engine load increases. To prevent a significant drop in vehicle power performance, the engine control system is usually equipped with an air conditioning idle speed boost device. 2. Throttle fails to provide sufficient vacuum: In carburetor and low-end electronic fuel injection engines, this device slightly opens the throttle through an electromagnetic or vacuum actuator. Therefore, even when the driver releases the accelerator pedal during braking, the throttle remains partially open. Under these conditions, the intake manifold behind the throttle cannot provide the normal vacuum level, leading to a corresponding decrease in braking performance.