Thread: Metering valve question

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I'm plumbing a brake system (Disc/drum) using a stayoff, or metering valve in the front lines. It is ECI part # EC526. It looks like this:


This is what it does:

Originally Posted by ECI catalog online

These valves are used for the front disc brakes in a disc/drum braking system to provide a "hold-off" feature so as to allow the rear drum brakes to actuate first.

The instructions say to install the valve so that the lines to either side of the car are equal length. This means that the preferrable location is on the center of the front crossmember, equidistant from each caliper.

My question is ...why? It is part of a hydraulic system with it's functionality being more dependant on pressure than flow, so why would it matter that one line is longer than the other? OEM systems have this valve built into the combination valve, and I don't recall ever seeing any car with the lines laid out so that the lines were equal length. (although my blazer has it on the forwardmost frame cross member, IIRC it's offset towards the drivers side.)

I don't really have a good place to mount the valve on the crossmember in this car, and folding up 2 extra feet of line on the drivers side of the car so the lines are equal length seems ....wrong.

I was going to ask Ralph at ECI, but it's winter time and he is grumpy.

Any input is appreciated.

Thanks for reading this,
Mikey
.

In a perfect world, they all would be mounted so the lines were equal length. It isn't really a big thing. One in a thousand will show some lag in operation of the farthest brake. Install it where it fits. If you notice a pull to one side on braking, you may have to do something different. If not, forget it.