A friend replaced rotted brake lines in my 91 accord dx, and since he put the put both fronts together on a proportioning valve and same for the rears, I'm pretty sure it's not put back together right, my haynes book says the pairs should be RF, LR and RL, RR.

How can I tell the in, out and rear ports on the proportioning valves? The car has disc front, drum rear.

Thanks