MC prop Valve, and residual valve

[Darksyde]

So I picked up a MC from a swap last year. Believe it's a GM, pretty large cast iron unit. 4 ports. Also got a basic Prop valve from an auto shop, and a couple 2 psi residuals.

First why four ports on the MC? I'm guessing for each wheel, but don't they use a prop valve with two ports? Could it be my MC has a built in prop? Then just need lines to each wheel?

Next where do the residuals go? If I put them after I need one more valve as the prop distributes to both brakes.

 

[oldmanb]

I'd say your mc is maybe an MBM unit, outlets out both sides, but pick a side, plug the other two. If you are using disc up front, drums on the back, you use a 2lb residual for the front, and a 10lb. on the back, as disc need less kept pressure due to their built in design in keeping the piston against the pads. I kept both my valves close to the master, before the prop valve.

 

[Bamamav]

Depends on where the master is going to if you need residual valves or not. If it's under the floor, you need them, on the firewall, you don't.

You probably have what is know as a Corvette style master, common aftermarket part. Use the ports on the side you want the lines to come out of, plug the other side. I had my brake light switch on the opposite side of the lines on mine, but went to a mechanical switch because the pressure switch never worked right for me.

 

[Darksyde]

Thanks!