Air leak

[Gardner Yeaw]

I have an air leak in the front of my 78FC33. Lying on the ground
and reaching up in the left front there is what looks like a
distribution valve. It has at least two thin black hoses attached
with screw on caps. When I shut off the coach it leaks for a few
minutes then stops. The brake tanks keep about 75 lbs of preasure,
but the step stops working.

There is a tube that is designed to have a rubber hose sliped over
it on one side of the valve, I can't see it, but that is where the
air is leaking from, It seemed odd that there would be a slip on
connection when all the others are the standard black tube with a
screw on connector.

Does anyone have any idea what this valve may be for? I had read
that the cruise control used air passing over a venturi to generate
vacuume, could this be it?

Thanks
Gardner
78FC33