So, I drilled out the grommets for the front drain tubes, tested them by pouring a mug of water and observing it getting pissed out the bottom, then went on with life for the past few months.

I've noticed that I've heard what seems to be a significant amount of water moving around overhead during periods of moderate to heavy rain, but none of it has gotten in so I figured it was just trapped in the sunroof area and would drain out when the vehicle hit the right incline to tilt the water forward or back. Today, however, my OnStar mic starting peeing on me like the old days. Is this a sign I need to drill out the rear drain tube grommets, too?

 

you can park "downhill" and test the front.

then park up hill and test the back.

thats about it.

oh they should both drain...

 

As long as they are clear, the front drains are sufficient. Check them again, by pouring a pitcher of water inside the channel. The water should drain out fast. If not, they need cleaned again. Soapy water or use a piece of trimmer line to clear the clog. I never did anything with my rear drains, and never a problem, since I cut the front grommet x out. Btw, the mic is on the front, so it appears your front drains are clogged again. GL

 

The rubber drain hoses are known to pop off the front nipple fittings at the drain trough which could also be the cause your leak. Check them out. The are espacially prone to get loose if you use compressed air or a line/wire to clear the drain.
You can add a ziptie to each to assure they won't come off down the road.



.

 

Thanks for the replies... can I see the nipple fittings if I remove the A-frame molding?

 

I had that same problem but it was the lights in the center of the truck, but the water was coming through my overhead switches and center dome lights box. So what I did was remove the light and put double-sided tape around the seal and put it back down and that fix the problem.

 

I got the rear grommets off and cut the tip off and reamed out a bit too. Did the fronts normally. But my trick is in a fast food drink straw with duct tape on it. I get warm water in a bottle fit tight to straw and squirt and release with a tight fit straw in drain hole. It squirts then sucks back and helps dislodge plugs. And prob under 5-10 psi so wont unlock tubes. Unless you feel like using your lips, but prob get spills in your mouth. Hope this helps.

 

Today, I went back to work on my drains tubes after more water in the floorboard and onstar mic.
I drilled out the crosses last year but it was not sufficient.

My key to success was weed-eater nylon wire. It was the appropriate flexibility/rigidity to thread through the clogs. I fed it up through the bottom until I could pull it out of the sunroof. There were 2 different places where I had to really work to get it through.
After getting it to the top, I tied a knot in the wire and pulled it back through the tubes.
When I pulled it back out, a LARGE amount of gunk came out as well as copious amounts of water. The water now drains FAST. I saw a minimal improvement last year by drilling out the crosses, but today was a huge difference.

Just thought I'd share my success in case it helped anyone out.

PS
King Joseph, you cannot see the nipple fittings for the A pillar, you will need to take the side panel off too. After that, you can pull the tube up through the A pillar for additional work.

 

when the glass is closed,only a small amount of water gets in. it has to leak a little. a rubbing with silicone grease 3-4 times a year keeps the rubber/metal seal in best condition.
anyone who gets a lot of dirt/water must be leaving the glass open in dusty, dirty conditions, debris like leaves in the air.
i open often when rolling to air it out and close up asap.

i have never detected ANY water inside,even just after/during a heavy rain.
i push a paper towell in and around in the rain.
it comes out dry.no water, no dirt,no clogged drains.

jfwiw.

 

I think this is going to be the key for me; I'm assuming the nipple fittings are still connected because otherwise the water would route down the A-pillar and not to the same places as before, right?

Did you perform this method with everything disassembled or did you go right through the grommet while it was plugged into the firewall?

Thanks for the tips...