Passenger side is tough, especially with big hands. When you put the grommet through the firewall just spin it, and give it a light pull to make sure it's secure. Then recheck like you did by pouring water and check for internal leaks.
Nice work! You just saved yourself alot of money!

 

Ok, so I'm at my wit's end with this damn sunroof leaking. Drilled out the grommets and it's still leaking... so I bought the weed wacker cable (same diameter as everyone else, .095 I believe) and rubbed my fingers raw pushing like 7 feet worth through the driver's side drain tube. I figured I'd tie a knot in it and pull it back through as others have suggested. I'm very gunshy about accessing the grommet from within the vehicle as I live in Seattle, it's been very rainy, and I think the tube is filled with water from wherever the clog is on up... with all the electronics under the dash, I have serious doubts that I could deftly pull the grommet off and aim it into a bucket in time.

Is there any way to get at this thing while the grommet is still plugged into the firewall? Even from under the vehicle, I never saw where the grommet comes out or the bright orange weed wacker tube protruding from it... although I could hear the thing moving around under the area with the wipers.

Thanks as always.

 

I know this sounds stupid but try using a fat drinking straw like from MC d's and put a tiny bit duct tape around the straw and put it in the drain opening and get water in a bottle or something and blow the water down in and you can feel if it is plugged. If it is just barely Suck back some water and blow and repeat. Call me crazy but I have done it a couple times and hasn't leaked in months. I also did the gromets mine had a whole handful of tree spills I would say caught all together messing up drainage.

 

King Joe
Get :
Shop Shop-Vac 6-Gallon 3-Peak-HP Shop Vacuum at Lowes.com

and:
Shop Shop-Vac Micro Cleaning Kit at Lowes.com


Disconnect hoses from firewall/grommet
Connect microtube to hose (inside the vehicle) and first suck out the tubes, then blow.
Do this a couple of times
Then put a balled up piece of paper in the roof reservoir hole, then blow out pipe again from inside the vehicle. The paper ball should go flying away.
If not, keep working it.

Also you might need to clean outside of the firewall as mine was loaded up with leaves. If you look at the front wheel well from outside the car, you see see a screw where the bottom trim connects to the vehicle. I unscrewed mine and seen there was a clump of leaves there. I took a wire hanger and scrapped out a handful of leaves from both sides.
Maybe your grommet is pressed up against some debris?

 

KJ,

The only way to get to the grommets without removing it from the firewall is to remove the front wheel well liners. The line penetrates the firewall behind those.

TRUST ME - that is WAY more hassle than it's worth.

Also trust that this is an easier fix than it sounds. I was very intimidated by it and managed to pull it off with only minor hiccups. And I'm not a car fix-it kinda guy.

Do the passenger side one first. That one's definitely the easiest of the two. Once you remove the trim panel the grommet is clearly visible on that side and easy to reach.

If you're concerned about water inside the vehicle, put a big bath towel on the floorboard. That should soak up more than enough water should it happen to spill.

Once you've tackled the passenger side, take a day or two to let it sink in and then try the driver's side. That one was a bit more of a challenge for me, but still relatively easy.

This is a pretty simple DIY fix, but you HAVE to pull those rubber grommets and trim out the rubber X for it to work.

 

Driver side was easier for me
Move drivers seat back all the way
Slide on back until you are looking UP at the steering column
Put hand up about a foot above parking break and you are grabbing the hose and grommet

Passenger side required taking off endcap and removing glove box, then snaking arm in endcap at an up angle, over some fan (squirrel cage) then back down, which I coudl just about get my finger tips on the hose/grommet

Bah - he'll learn and have a cool Hummer scar to brag about to his children and great grand children

 

Thanks - clarification, though: I already did the grommet mod.

My problem is that the lines are STILL clogged... I tried fishing weed wacker line through so I could tie a knot in it and dislodge any debris, but it doesn't do any good if I can't get to both sides to "floss" the tubes, so to speak. As the tubes are presumably loaded with water, I'm very nervous about pulling the grommet free of the firewall and having it dump all over the electronics. Does that make more sense now?

I'm debating if maybe I need to mod the rear grommets, although I haven't seen any DIYs on that and really have no idea to get to them. My interior is getting soaked though and I imagine it's only a matter of time before permanent damage is done.

 

X2 Atari... there is a metal tab in the pass side that scrapes you too.

 

I have been dealing with this problem since 2010 thank you for a clear answer.

 

Hi. i know what you are going through. and fear of water on the electronics is justified. i ended up with over $900 worth of repairs before i got smart enough to join the Hummer Forum. what everyone is telling you is true. lots of different things to try, but pulling those grommets and cutting out the rubber is the only answer. everyone has a wife, girlfriend, son, or daughter with small hands. that is a big help and they will love to get involved. they can reach those grommets without tearing the vehicle half apart. my girlfriend did the reaching for me and we got it done in 1 afternoon. as the other posts suggested, when the grommets are out, run some wacker line through the firewall holes. once those are clear, do the same from the roof down. keep sending a little water down until it is running free. it can be time consuming, frustrating and cause much foul language. don't give up, be patient. everyone else did it, i did it, you can too. once it is finished, remember the maintenance. keep them cleaned out. an air compressor w/a regulator can be turned down to the point of just a small amount of pressure. gently blow them out now and then and check the flow. it will be worth it. and remember to thank everyone here who has felt your pain. they are great people.