Brake pressure reduction valves on rear wheels
I am not a Ford owner myself, but being "the car guy" among my friends and recklessly helpful at times, I agreed to fix the broken rear brakes on my friends Ford Mondeo 1997 station wagon (2.0i, BNP, European). This got me cornered with one rather rookie question: Which way does the pressure reduction valves on the rear wheels go?
Basically, one of the rear brake lines had failed and both were hopelessly rusted (where they go above the gas tank, over the rear axle, and to the brake hose at the wheel), so I was just going to replace the lines. However, on the brake lines, just above the rear axle, there were a couple of pressure reduction valves, one per wheel. I couldn't get the brake line ends off due to all the rust and crap, and actually broke one of them trying to unscrew things. No big deal, got a new pair cheap on eBay.
Only problem now is I don't remember which way they go, and can't find the pictures I took of it a few weeks ago when I got them out. I do remember something about "the bigger end forward" (as in connecting to the master cylinder up front), but I don't remember if it was the bigger outer part, or the bigger thread.
If you look at the attached picture, the top part is a bit bigger, but has M10x1 thread. The lower more narrow part has M12x1 thread. And I imagine it won't work too well if I have it backwards. Can someone enlighten me on which way it should go (which end connects to the line to the front of the car, and which end connects to the caliper at the wheel), to give me better odds than 50/50?