The Stovebolt Site Forums The Shop Area Paint and Body Shop It's raining. My windshield leaks

And though I've searched and calked for years with several repop gaskets, installed with windshield bedding compound or silicone or plumbers putty or all three it still leaks. As I drive it drips off the bottom of the dashboard onto my pant leg and then into my sock. As the warm air from the heater evaporates the water it condenses on the windshield making it miserable. Is there somewhere in the body seams that water can get into the windshield area and mimic a gasket leak? It comes from the lower left corner of the WS. It takes about ten minutes at highway speed to start dripping. When it's sitting still it may take several hours to drip. So it seems that wind is driving the water into somewhere I haven't considered.

Can it possibly be from the cowl vent or do you see it on top of the dash?

Check the screws that hold the front cowl/hood seal on. The Book calls for sealant on the threads of those screws.

Get the garden hose out. Make it "rain" on your truck. Lay on the floor while looking up at the dash in the area of question. A bright flashlight helps greatly. Run the hose until you find the leak. If you feel that you've spent enough time staring at one area without results, re-adjust the hose. Water will travel from a source, across things, just to annoy your leg.

Tip: Masking tape helps hold the hose in certain spots so you don't have to hire an un-willing helper.

I can see water running from under the screw-on molding at the lower left corner and down over the top/front of the dash. Doesn't happen on the right. I cured the cowl vent leak a couple of years ago with a new rubber drain hose and a gasket. I forgot to mention that it's a '51 AD cab in case that wasn't apparent. Fortunately today's drive was mostly bare and dry except for a little light rain at the end of my 6-hour trip and that didn't cause a leak. I suppose I could take the molding off and watch where it comes around the gasket.

It sounds like the leak is coming from the windshield gasket itself. You might be able to add some sealant between the glass and the gasket on the outside. It could also be getting under the gasket at the top between the sheet metal and gasket and running down to where you're seeing it.

The ultimate fix would likely be removing the windshield and replacing the gasket with new sealant.

They sell a tube of really runny windshield sealant at most auto parts stores which works very well for our leaky windshields. It's clear and very runny which allows it to flow deep down into where the leak is. I recommend using a lot of painters tape to keep excess off the paint and the exposed part of the rubber windshield seal.