The Stovebolt Site Forums The Shop Area Driveline Dual circuit brake system parts diagrams

In the diagram for a drum/drum system (in my orginal post) there is a "metering valve" in the line to the front brakes. The description says this is to prevent "nose dive". I found this one https://www.speedwaymotors.com/Brake-Metering-Hold-Off-Valve,8904.html?sku=91031363. Speedway says this is the valve that allows the rear brakes to set up a little sooner than the front brakes. Does anyone have one of these installed in their truck? Is it really necessary?

Edit: I asked the question too soon. The answer was right in front of me thanks to the all-powerful Google. The Summit Racing web site states, "A brake metering valve is used to Balance the Braking Forces. It is only found on vehicles with front disc and rear drum brakes. The metering valve holds back fluid to the front brakes until enough pressure is created to overcome the return springs inside the rear drums. It is also known as a “metering block.”

The metering valve is plumbed into the system immediately after the Master Cylinder. In many vehicles, the metering valve is part of the Combination Valve."

I think I'll install my brake system without this valve. After I've been able to drive the truck around a bit I can then decide if I need to add one or not.