[GoremanX]

Yesterday I noticed some water in the spare tire well of my 96 RMW. I dried it all out in preparation for some rust repair in that area. I didn't drive anywhere after doing this, just left the car in the driveway. It rained a lot overnight. This morning, there was water in the spare tire well again.

I checked all over, and it doesn't appear to be coming from very far, somewhere near the bottom of the taillight is my guess. Everything above that is clean and dry. I then pulled out the trim panel on the other side of the car (the one with the locking compartment), and sure enough there was a bit of wetness in there, too. Not standing water, just obvious moisture and some resulting rust. Again, doesn't seem to be coming from very far, probably somewhere just below the taillight. Doesn't appear to be the rubber grommet, though.

Is there some common leakage area around those spots I should be watching out for? Something that needs seam sealer applied? Or is this unique to my car and I should start spraying water at it to find out where it's coming from? I don't currently have a functioning outside hose spigot, so setting up a hose is a chore...

 

[Fix Until Broke]

I'd start spraying water and find the source if at all possible. Maybe use a hand held spray bottle? Set on a narrow stream, you can punch some water in the cracks/crevices in a very controlled manner to help figure out where it's coming from?

 

[Fred Kiehl]

I would look at the seams under the edges of the roof rack first. The sealant dries out, and cracks. Gouge all of the sealant out, and replace it with new sealant. I used ordinary roof cement/sealer from the local hardware store. Make sure you keep the sealer at the same level as originally installed, so you can reinstall the roof rack. You can put tape on both sides at the original level to give you a reference. When I was trying to cure my leaks, I tried everything else before redoing the sealant. The sealant was the last possible thing to do, and it worked, and I could have saved a lot of other work trying to find the leak. One caution...be careful removing the screws holding the roof rack sides in place. They can turn the rivnuts in the body. I would shoot some freeze-off on the base at the body before trying to remove them. If they do turn the rivnut, you must remove the headliner to get to them from the inside. The rivnuts are not available anywhere, but there are some SAE sizes that can be used to replace them. You need a tool either bought, or home made to install them.

The other possibilities are the top cargo bay window seal, and the rear of the vista glass.

 

[Fix Until Broke]

Here's the rivnuts - There are 12 on the car if you want to replace them all. M5x0.8

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Virtually indistinguishable from the factory originals - A couple millimetrers longer, but still shorter than the screws themselves. Also stainless so they won't rust up again.

Here is one option for a tool to set them - Combination Rivet Nut And Pop Rivet Setter Kit | Astro Pneumatic Tools
Many other options available, but this is good value for the wide range of things that it can do.

I used the above tool to "reset" the rivnuts that didn't spin to help insure they don't spin in the future.

Also used Permatex 80632 on the bolts that screw into them after cleaning up the threads. The factory bolts are stainless so this helps to prevent galling (though they're not torqued very tight so shoudln't be an issue).

Permatex® Thread Sealant With PTFE, 4 OZ. – Permatex

www.permatex.com

 

[Fred Kiehl]

Here's the rivnuts - There are 12 on the car if you want to replace them all. M5x0.8

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Virtually indistinguishable from the factory originals - A couple millimetrers longer, but still shorter than the screws themselves. Also stainless so they won't rust up again.

Here is one option for a tool to set them - Combination Rivet Nut And Pop Rivet Setter Kit | Astro Pneumatic Tools
Many other options available, but this is good value for the wide range of things that it can do.

I used the above tool to "reset" the rivnuts that didn't spin to help insure they don't spin in the future.

Also used Permatex 80632 on the bolts that screw into them after cleaning up the threads. The factory bolts are stainless so this helps to prevent galling (though they're not torqued very tight so shoudln't be an issue).

Permatex® Thread Sealant With PTFE, 4 OZ. – Permatex

www.permatex.com

Those do not fit. They are too small for the hole. The GM parts are bastard sized, and have a sealing gasket at the top. I have tried that size a couple of years ago, and bought the last 6 OEM parts available anywhere for about $5 each. The only ones that can be made to fit are an SAE size that is just slightly larger than the original hole. You must turn the heads of the SAE screws down slightly to get them between the channel sides. BTDTHTTS.

Do NOT replace them with wellnuts, they are not made to take a load, and will pull out if you tie something to the roof rack.

 

[Fix Until Broke]

Fred - I've read at least a dozen threads where you state there are no parts available and only one way to do it, just like the above. Well, there's several ways to skin this cat.

If you want ones with the same "bastard" diameter as the GM ones - here they are in zinc plated steel just like OEM (no sealing washer) - McMaster-Carr
If you want ones with the sealing gasket (in the same bastard size) - here they are in aluminum - McMaster-Carr
Buy both and put the sealing gasket on the steel ones if you want to go that route for a total of ~$2/each
Put some sealant on the zinc steel ones for $0.75/each

There's rubber coated brass ones if you're willing to drill out the holes in the roof a bit, still using the original screws - guessing these might spin more easily(?) and they require drilling - McMaster-Carr

I went with the stainless ones which are a bit (0.027") smaller in diameter at the body as you state. The top flange covers the hole completely, even if pushed all the way to one side. The rivet part below bulges out to also completely cover the hole from below. The Permatex gasket maker seals them up to the body top and bottom, and the thread sealer seals the threads and helps to be able to remove them in the future since the OEM bolts are stainless too.

These are 4 additional options that anyone can choose from, or come up with even more options that might be better than either of our solutions.

Stainless one on the left, removed OEM on the right.

OEM Diameter which is ~0.005" smaller than the resultant hole in the roof

Stainless diameter

OEM Installed

Stainless Installed

GoremanX - sorry to derail (pun intended) this thread - hopefully this is useful if you need to remove the roof rack to track down your source of water ingress.

 

[Fred Kiehl]

The rubber ones are not suited to the rack, because they will pull out with much less force than the metal ones. The slider rails on the top of the roof use the rubber ones because they are not used to hold the load to the car.

The zinc coated ones are about the same size as the OEM parts, so should work best. They are about 0.25 mm larger in diameter than the OEM unit (I measured one with my caliper). I have not come across the ones you referred to before today, and will add the zinc coated one to my list of best fit parts available.

The stainless ones that are substantially smaller tend to cock in the hole as the one you showed in the picture. If the shank does not fill the hole completely, that is the consequence, because it is not supported completely and evenly around the top lip.

There may be other ways to accomplish a task, but sometimes the task is easiest if done in a particular way. I invariably have done the task I comment on, and found the way I state the easiest, with the least damage to the original parts, and least costly at the time of my writing. If something is produced since my writing, or someone finds a better way, I am open to it. So this is back on the proverbial rails.

 

[GoremanX]

I think I found where the leaks are:



Both sides are like that 🙄