A metering valve is used in the line supplying pressure to the front disc brakes in order to:

Prepare for the Automotive Service Technician Period 1 exam. Study with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

The main idea here is timing of when front brakes start to take braking force. A metering valve in a front-disc, rear-drum brake system delays the initial pressure reaching the front brakes. By holding back front-brake pressure just a moment, the rear brakes begin to apply first, helping to keep the vehicle stable during the very first portion of the pedal travel. This reduces nose dive and lowers the risk of front-wheel lockup because the braking effort is more evenly distributed as you begin to stop. The valve isn’t about increasing pressure; it’s about slowing the front brakes' response until the rear brakes have already started to engage.