On vehicles with rear drum brakes and front disc brakes, the metering valve ensures that drum brakes receive hydraulic pressure ______

The metering valve plays a crucial role in vehicles that utilize both drum brakes and disc brakes by managing the hydraulic pressure to ensure optimal braking performance. In systems where rear drum brakes are paired with front disc brakes, the metering valve is designed to provide hydraulic pressure to the rear drum brakes slightly before it delivers pressure to the front disc brakes.

This sequencing is important because drum brakes tend to have a more substantial tendency to lock up compared to disc brakes. By applying pressure to the drum brakes first, the metering valve allows the rear brakes to engage just enough to prevent the rear wheels from losing traction before the front brakes start to engage more fully. This helps maintain stability and control during braking, particularly in situations where the brakes are applied hard.

The timing of this pressure application ensures a balanced braking force across all wheels, promoting effective stopping power while reducing the risk of skidding or uncontrolled vehicle dynamics. Therefore, the correct choice correctly reflects the function of the metering valve in a rear drum and front disc brake system.