Bad Water Leak Somewhere

[68 Ford Stepside]

While driving my '68 Flareside the other day it poured down rain. The water started coming inside on the right side of the cab like a river. Somewhere behind the right vent box area. I guess I need to remove the glove box & the right hand vent box to try & determine where this major leak is coming from.

[HIO Silver]

Before doing so, check the right footwell vent bowl.. it's prolly packed with debris and overflowing.

Unclip/peel back the rubber or tar paper shield at the rear of the front fenderwell and you'll see it. Fashion a hook out of a piece of coat hanger and start fishing it out to unclog it. Run some water down the cowl vent (at the base of the windshield) until it runs clear. Oh, ya might want to avoid doing it at the same time cuz water will run down your arm and soak your shirt... ask me how I know.

[basketcase0302]

and start praying your cowl area isn't rusted out! Next to impossible to replace, (I did not say can't be done).
I cleaned my cowl area with shop vac / water / air pressure / about 6 hours later I was satisfied with how clear the water was that I was flushing down the cowl in front of the windshield.
Also look at your wiper arm gaskets, (up under the dash with flashlight) while someone else sprays the hose on the cowl area.

[HIO Silver]

and start praying your cowl area isn't rusted out! Next to impossible to replace, (I did not say can't be done).
I cleaned my cowl area with shop vac / water / air pressure / about 6 hours later I was satisfied with how clear the water was that I was flushing down the cowl in front of the windshield.

You're right. It can be done but it is TONS of work. The cowl is a "balloon assembly". Meaning, it is welded together just like my 65 and 68 'Stangs. Ya have to remove the hood, fenders, windshield and then drill out a gazillion spot welds holding the upper and bottom halves together. These rigs have their vents on the side which is a blessing. On 'Stangs, the vent is on top and called a "hat" (like a top hat with an open top) which is welded to the bottom half with nary any seam sealer applied. Dirt, leaves, etc. gets dammed up rather easily and rots out the hat area... my 65 was slated for surgery this year until a house remodel fell out of the sky... sometimes it sucks being a part time property manager!

Cleaning out my vent bowls took 1.5 hours... it musta had six inches of mulch in each of 'em.