Tahoe rear hatch leak

[east302]

I'm getting water through the hatch on my 98 Tahoe. It has the tailgate/liftglass combo and I have replaced all of the weatherstripping: top piece near third brake light, the gasket surrounding the cargo opening and the piece on top of the tailgate.

Water is coming down from the roof over the top of this piece on the tailgate...

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When the glass is shut, you can see a gap of about 1/8" between the bottom of the lift glass frame and this rubber gasket. Same for both sides, but the left (driver) side is about 1/16".

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If this rubber piece were taller, it would seat against the metal on the lift gate when closed. Am I missing any weatherstripping on the lift gate?

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There doesn't seem to be any play in the hinges, but the body lines look a little uneven, especially on the right which is where the gap between the gasket and liftgate is greatest.

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When closed, the glass is about 1/4" out from being flush with the pillar...

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Any suggestions? Am I missing weatherstripping on the bottom of the liftgate?

 

[deadbeat]

It shouldn't stick out as far as it does, is the latch broken?

 

[east302]

Not that I can tell. It functions fine, and I adjusted it forward as much as it allows. I can push on the glass and it doesn't go in any more...seems like it would if the latch was weak.

The tailgate sits about 1/8" lower on the passenger side than the driver side. I'm sure that is making the gap in the gasket worse, but the hinges do not appear to have any play in them. That is, the bushings don't seem worn like they do on the front doors.

I'm about at a loss on this one.




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[deadbeat]

The gate looks fine, water doesn't run up hill, not sure how it would run over the rubber. It looks like you have hosed it and watched, you are sure 100% that it is running over that rubber? Looks like if it went down by the seal in that pic that it would just run right on down into the floor board or out.

 

[east302]

I think that's how it is supposed to work.

In the first picture, the lift glass metal frame is supposed to seal on the vertical bubble gasket. It's not a tight fit (glass isn't pushing in enough) so it's traveling down in between the lift glass metal and bubble gasket until it hits that horizontal gasket at the top of the tailgate. Since the horizontal piece isn't flush with the lift glass metal (there's about 1/8" gap) it goes through the gap into the cargo area.

I tried adding weatherstripping to the lift glass metal frame and it didn't work.

If I could get the lift glass frame to go in more and the tailgate to come up, it would seal the gap. It only takes about ten seconds of water hose flow to start a river in there.


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[ryansusername00]

I'm having the same problem described. Was there ever any resolution found?

I just replaced the entire weather stripping after having two small leaks near the top of the rear hatch. That small leak is gone but now I have a much bigger through the sides.

The rear hatch window sticks out just as far, though I do not remember it sticking out as far before I changed the weather stripping.

I did adjust the striker on the rear hatch, so maybe that is causing the window to stick out that far.

 

[east302]

About twice a year, I monkey around with it trying to find that magic solution. The things that did work:

1. Stuffing a gasket and RTV underneath the end of the piece that is on the corner of the tailgate. There’s a plastic Xmas tree clip that holds it down. This raised it up, closing the gap between it and the metal part of the liftglass.

2. Slicing drain holes in the weatherstrip at the floor. Water was getting onto it and overflowing into the cargo area. This lets it drain out and may just be the way to go in the first place.

I really think this was a manufacturing defect on my particular truck as no amount of hinge adjustment ever worked. There is no way that GM required that level of precision and adjustment at the factory and the factory manual has no long epistle on adjustment.

The previous owner (since new) commented that it always leaked a little, but chalked it up to getting dirt and debris in the weatherstrip channel. Too, he always had it in a garage so I got the impression that it wasn’t something that he thought much of.

Your post prompted me to pull the two backer rods out of my weatherstrip since these obviously keep the glass from going completely flush. I cut a small slit (there’s a hole near them in the weatherstrip already) and took them out. These are near the taillights and were added under a TSB in an effort to reduce leaks.

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The glass closes in much better now. Near perfect on the driver side and better on the passenger. I’ll have to do a water test to confirm, but can replace the backer rods if needed. They slide in and out fairly easily.

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[ryansusername00]

I appreciate the reply on this old thread

I new weather stripping that I replaced was the GM "revised" part - or at least I believe it was.

The new weather strip had two dots of color that were suppose to be lined up with the top of the bottom door. I noticed that the "backing rod" stuff lined up on both sides around these dots. So it seemed like when the door would shut, the rubber would make the most pressure around the bottom door.

Well it's only been a couple of weeks, and I noticed that the left side "backing rod" has fallen down quite a bit.

Before I replaced the weatherstripping I did try to add more of that backing rod to the entire weather strip (following that youtube video from 1Road). That seemed like it would help but it still leaked.

I'm going to try your approach, just pulling the whole rod out.

I'm glad you made the comment about it being potentially just a defective part. I've adjusted a lot of variables, and then got to the point of just throwing money at it for new parts and the problem persists.

I did spend a few hours at the junk yard over the weekend. I went into 4-5 lift gate models and it was interesting how some definitely did not leak but others did leak. They all had a very visible gap of light between the door and window.

I do keep wondering if maybe the rear door was bent. I had my Dad help me replace the rear window to replace that top weather stripping about 9 months ago and at the time I was worried about our combined weight on the tailgate. My Dad did not appreciate me pointing out my concern about the weight because he contributed a majority of that weight

There doesn't seem to be any play in my rear tailgate but I did pick up some bushings from LMC that I might try. While at the junk yard I did pull one of the non-leaky vehicles rear door pin. To add more into the mystery, that door pin was very clearly bent but I couldn't tell until I started removing the pin. The door with the bent pin did not have any slop either, and no leaks, so I surprised that the pin was bent.

If I end up finding replacement pins I might just replace mine. Couldn't hurt I figure.

If either of the brackets that the pin connects are bent.. Well that might be a hard problem to solve. They look fine though.

 

[ryansusername00]

So I tried many different ideas for preventing the water leak. I tried ordering some pins for the lower end of the tailgate. Every online distributor would cancel a few days after I ordered (no one seems to have that part still in stock).

In the end, I just got fed up and drilled a couple of holes in the inside of the weather stripping lip. Any water that would make its way inside would drain before getting to the carpet which was "good enough" for me. About a week later, I put all the trim pieces back together and I have had a dry carpet now for a couple of months. Gone through some very serious rainstorms in that time. Could still be just complete luck but I have used that hatch dozens of times in that time span.

I think the biggest help after the drain holes, could have been putting the trim pieces back.. If so, it would be coincidental because I just kept the trim pieces off while I was debugging the root cause of the water leak and only wanted to put it all back together once I figured out the problem/s.

It is hard to say if it is just anecdotal or not, but the order of things that I replaced are,
- Removed trim pieces around weather stripping
- Re-stuffed/re-sealed original weather stripping
- Replaced original weather stripping with "new" revised oem weather stripping (still had a leak but maybe this was because I did not put the trim pieces back)
- Got fed up and drill holes in inside of weather strip lip on both sides. Any water making its way past the weather stripping would drain through the holes (may need to periodically clean holes, really not the best solution but good enough for a 25 year old vehicle)
- Put all the trim back around the weather stripping.

I do not see water pooling over the floor trim plate, which I really assumed that I would based on how it leaked from the rear window over the weather stripping.. If I ever have time I'll take off the trim floor plate after a rainstorm and see if water is still getting to the drain holes still or if the trim pieces actually do help to prevent water from getting past weather stripping. It almost seems like the trim pieces force the water to remain in the weather striping channel though I would think if this is true, it is more a result of just shear luck than by any deliberate design/engineering choice made by GM with the weather stripping.

There is a chance that water is somehow running over weather stripping and running underneath the trim pieces and draining out the drain holes. If so, I am honestly fine with it at this point..

I'll attach a couple of photos and also link to whole album here,

I've had it with rain leaking..

10 new items added to shared album

photos.app.goo.gl

 

[east302]

Hey thanks for the update and for adding the photos.

When I removed the backer rods from the weatherstripping, the glass closed more flush and the gap between the top of the tailgate and bottom of the hatch was reduced.

I shouldn’t have gotten my hopes up. It then leaked down between weatherstripping and that little tab on the tailgate strip…

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…which mimics what your video shows so the backer rod does seem to help. It just pushes the glass out further and increases the gap between the hatch and tailgate which I think was just installed wrong to begin with. Your comment about seeing junkyard trucks with the same gap may give credence to that.

With or without the backer rod, it still gets water into that lower weatherstrip channel. It’s much less with the backer rod in place (and the RTV filling in the gap between the tailgate and hatch) but still seems to find a way in through my RTV gap. Mine fills with water in the same place that yours does in the photos.

Where you drilled holes on the inside to give it an exit, I cut the bulb part of the strip so it overflows to the outside. Same concept - it gives the water a place to go instead of trying (and failing) to keep it out.

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I tried to slope the bottom strip down toward the center where the ends meet. It wasn’t successful - it would pool at the corners - so cutting the strip seems to work and save my sanity.

I do agree that the plastic trim on the bottom tends to form a dam. Probably accidental on GM’s part.