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Midgate Service Bulletin?


Charter Member
SM 2003
Full Member
Feb 27, 2002
Twin Cities, MN
If any of you are signed up on the ChevyAvalanche Yahoo group, you have seen the emails. There have been a few emails circulating on that Yahoo group that there is a Midgate service bulletin.

Knowledgeable folks, please come forward!

Seems like there was something on the gasket leaking on the midgate. This was the cause of water in the rear seating area??

Thanks to WS6Y2K and aVOLanche, I have the 2 pdf file TSBs from GM. I would like to post them in this thread but am not sure if we have the "right" to do so. Chief, answer this for me so I can post them here.

Aegis, you are right though. The two TSBs refer to thicknesses and gaps and show how to check your stuff.

They gave me a copy of an Administrative Message that went out to all dealers regarding the AVs and EXTs. It's dated 4/14/02:

"If water leak repairs have been attempted because of a wet carpet and the condition continues to exist, take the following steps:

1. Remove the "C" pillar inner trim on both sides of the vehicle.

2. A large rectangular opening provides access to a pocket at the lower end of the "C" pillar.

3. Check for water in the pocket.

4. If water is present, you will need to provide a drain path. One way of doing this is to obtain a piece of steel rod, approximately 18" long and push it through a seam of expandable sealer at the bottom of the pocket. The sealer is easily detectable as the end of the rod contacts it."
I don't think TSB's fall under "copyrighted" works - I mean it is basically a repair procedure document for a piece of machinery. So I don't see the issue of linking them up here...
Regarding the 18" steel rod...is this inserted from below the vehicle or from inside the pillar?


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Thanks,Jamie.But the REAL kudos go to George(WS6Y2K).He supplied these to me(and others).Great find,George.Thanks for posting,Jamie. :B:

<i>THis close tolerance rubber material may be purchased from Kent Automotive, 800-654-6333, . THis material is sold in bulk for. <b>There is enough material to do 25 vehicles.</b></i>

I am going to call to see how much a box is and do this job proactively. (I don't have any leaks.) :)

If I buy a whole box will others buy the rest and reimburse me actual costs and shipping for the rest of it so they can also do the job proactively?

1. I agree the real thanks should not ignore George, the original source of the TSBs which I received and was also prepared to post (I don't see much, if any, liability for you Chief, especialy if one of us posts it).

2. I just had this work done for free at the local Chevy dealer (they didn't even sell me my Av) so why would I pay money and spend the time myslef to do it? But hey, if you want to diy, I can support you on your right to do so. I left copies of the two TSBs on my seat when I dropped the Av off for their perusal (and suggested that they might be relevant in my work order note), dirty thumb prints all over them confirm that they were looked at.
Kudos for posting the TSB's! I'm due to take my AV in to the dealer for the 7500 mile service and some other little odds and ends. My leaks are one of them. I really don't get too much water in the vehicle. Some water collects at the base of the midgate, but has never reached the point of dampening the carpet. I have two noticeable leaks in the bed, between panels 1 & 2 on the drivers side, and where panel 1 meets the midgate on the drivers side. The last leak I mentioned is probably the worst, if I had anything back there in a serious rain, it would be definitely wet. DLeaving the TSB's in the front of the vehicle is also an excellent idea. If anything it will keep 'em honest. Have a good one!
jackalanche said:
2. I just had this work done for free at the local Chevy dealer (they didn't even sell me my Av) so why would I pay money and spend the time myslef to do it? But hey, if you want to diy, I can support you on your right to do so.

Couple of reasons. My dealer is 20 minutes or so on a good day. It is a pain to get my wife to drop me off and then I have to make arrangements to go 45 minutes the other way to work. They would probably keep it a day or so.

Not worth all of that for an easy fix.

An hour or so of my time on the weekend is cheaper than an hour of my time during the week. (Of course I would spend several hours of my time being wasted during the week.)

Blown engine, it goes back. Little stuff, DIY.

Thanks to all that got the TSB package together and to us. That will be great leverage if there is a reluctance to do the work properly.

A question: Has anyone that had serious leaks gotten them 100% fixed, or is some leaking what we have to learn to live with?