OK, A while back I posted up a suggestion to seal your roof rack bolts to prevent leakage into your cab, Well...
Turns out that just sealing the bolt threads is not enough. Next big rain I had wet floorboards and headliner. Today with the help of a local FJ bro(LGTiny) We tore into it to find the real culprit.
Here is a pic of the mounting point with the covers off and rack unbolted. You can see all the dirt and crap that collects in there, The crud was so thick and cement hard, I used carb cleaner and a Q-tip just to clean around the bolt sleeves.
Now some of the area around the sleeves was clean, as it all should be, BUT there was a LOT of areas where the mud was all the way up to the sleeve edges. Herein lies the problem.
Notice the gap around the sleeves. THIS is where the water gets in, not down the bolt threads.
The stock bracket that lays in this channel has some paper thin rubber gaskets on it that for 3 years did a good job of sealing, but after years of desert heat, granular particulates (tiny sand and dirt) combined with flex and vibration finally did these guys in.
Here is the bracket and gasket I'm referring to.
The gasket actually looks thicker in this pic due to the angle, but 7 out of 12 of them were shredded or had holes worn through.
There are spacers that sit on top of this bracket that push it down for a seal with another small rubber gasket that in most cases was also crushed and deteriorating.
After Step 1 which was cleaning the area, came step 2. A big gray blob of roof flashing (there are many types of sealant that would work, this is just what I had laying around) over the sleeves and surrounding surface.
Then pop the bracket back in.
And a top glob just for good measure. Cause I ain't doin this again!
Then re-install the spacer sleeves.
Now do this 5 more times on the roof, and the rack is ready to be re installed. The amount of sealant in the hole of the sleeve should be more than adequate to seal the threads.
So Morale of the story is do it right the first time. and dont trust stock crap, always go the extra mile or you will have trouble down the road