[Gearhead999]

I looked at my shop manual this morning and see what you're talking about.

I've never seen one hooked up like that. I wouldn't worry about it.

It was probably the way they were going to route it in the beginning and then made a change before production or shortly after it started.

If the valve was bad the engine would stall all the times, because the valve has vacume all the time, not just when you step on the brake pedal. Sounds like the diaphram is leaking in the booster.