Water leak cargo area

[JDFBear]

So I have a water leak in the cargo area of my 1999 Sport. It drips from the middle of the window surround onto the wheel hump and the carpet. The window isn't wet and the headliner isn't. Only thing I can think is the roof rack so I pulled it off but I don't see obvious ways unless it's coming through the screw holes. I'm going to paint the rack and put it back sealing the screw holes.
I'm just wondering if there is a common place these explorers like to leak

 

[4wdExplr]

Jeff,

I did a quick search and found this:

Leaky Rear Side Window Fix

maybe my experience will help someone with a similar problem. I had suspected one of the roof rack screws had been leaking on my '00 Mountaineer. after removing the rack, to strip and repaint it, i put sealant on the screws and assumed that would fix the problem. we'll, it's been pouring rain...

www.explorerforum.com

It looks to be the same issue you are describing.

 

[German Engineer]

Check the hinges of the glass window in the liftgate. These screws like to come lose, and when they do, then the glass can wiggle around a bit (even when it's closed) and the window won't seal right.
That's my best guess along with Jeff's suggestion to check the rear side windows.
You might also want to check the big seal that goes all around the liftgate as well.

There are also these two big bolts on the left and right that the lock mechanism of the liftgate holds onto when it's closed.
Just like the ones on the doors, they're also supposed to have some odd plastic cover around them which tends to wear and break throughout the years. OEM replacements for those are kind of pricey, but you can fix that issue super easily by cutting a suitable hose to the right length and slicing open lengthwise to make a rubber piece that you can slip onto the bolt. It'll stay in place by itself, there's no need to glue anything and it needs to be able to roll around on the bolt anyways.
This fix won't last forever but it's super quick and easy, super cheap and it may easily get you through a couple of years before you need to fix it again.
The doors like to make rattling noises when those grey plastic pieces around these bolts have worn out and have gone missing, the liftgate may not rattle so much, but it could lead to a leaky seal as well.

 

[CDW6212R]

The rear quarter glass is prone to leak after 20 years. The sealant is hard and sometimes a gap, a break develops. If you can use a water hose to confirm that's it, then you can decide best how to fix it. I'd sray the top edge of that glass with a water hose, and see if you can make it leak there. If that's it, the answer is to R&R the glass and reseal the perimeter, or carefully spread a thin line of Ultra Black RTV along the top edge of the seal outside. I've done that on three of my 90's Explorers. Only my 99 hasn't leaked, I had that glass out when I got it to reconstruct it(so that sealant is newer).

 

[allmyEXes]

Almost all of mine the rear side glass leaks. I fixed one out of the 12 glasses. When I purchased the '91 one of the rear side glasses was broke out. I used a 3-M sealer called 8609. I'm going to fix the others as I have the headliner boards out to replace the headliner because the trim has to be loosened up anyway to remove the board. I hope this helps and just yesterday I just noticed the RR glass is leaking in the white '97.

 

[J_C]

I wonder what effect it would have on the seals if a few coats of AT-205 were put on the rear side window trim. I forget the technical term for what it does but it reconditions rubber to make it more flexible again. Most of mine are intact but have become very hard rubber, though the bottom edge on one side has the surface deteriorated away so it has a grainy texture that is probably too far gone for any improvement. None leak yet.

Anyway, first thing i'd do is pull the interior trim panel off to get a better look, BUT I would do it in a heated garage, and/or consider pointing a fan based electric space heater at it. 20+ year old brittle plastic is even more brittle when cold.

 

[CDW6212R]

I wonder what effect it would have on the seals if a few coats of AT-205 were put on the rear side window trim. I forget the technical term for what it does but it reconditions rubber to make it more flexible again. Most of mine are intact but have become very hard rubber, though the bottom edge on one side has the surface deteriorated away so it has a grainy texture that is probably too far gone for any improvement. None leak yet.

Anyway, first thing i'd do is pull the interior trim panel off to get a better look, BUT I would do it in a heated garage. 20+ year old brittle plastic is even more brittle when cold.

The quarter glass windows have a very large surface rubber component surrounding the whole thing. The outer part visible is a distance away from the sealing surface, so nothing can improve the seal. The seal itself is an applied material like caulk, similar to an applied windshield sealant. So the heat and age hardens the sealant and some twisting of the body breaks the bond somewhere. I have the two original 99 quarter glass pieces to install into my 99 some day. I used my entire 93 rear body to reconstruct my 99, so the 93 glass in it I helped to install about three years before.

The 95-2001+ quarter glass has that outer rubber degrade after this long, yes the surface becomes very hard and rough. That can be painted but I doubt many people have done that yet.

 

[J_C]

^ I doubt paint would stick well (definitely not on mine because see below, it's been silicone greased), maybe for someone who hasn't greased theirs, something like vinyl dye would seep in enough that it wouldn't crack or chip off, but I am not as concerned about the appearance (which is really quite good for its age with the grease film making it darker and shiny, except for the one rough area) as that even if it is not the primary window seal, when newer and still more the flexible consistency of rubber, that did help keep water from getting past it to the primary window seal. Even now in its aged state, I can tell that it blocks water entry all by itself by applying a few drops of water and seeing it all bead off instead of wicking down in between.

Granted, I have put silicone grease paste on them so a little may have worked its way between that rubber and the metal and glass and this is why it still seems to seal well, or some past wax did, but I couldn't have gotten much silicone grease between the rubber and metal/glass because I was careful not to get much on the glass, due to it being a fair amount of effort to wash silicone grease off of anything. Detergent doesn't cut it so I basically have to rub until it's gone, with glass being visually unforgiving of any greasy residue. I've considered using masking tape on the glass the next time I grease them.

 

[CDW6212R]

Yes, paint won't adhere well at all to a surface with a porous surface or repellent chemicals in it. Using silicone on any outside vehicle surface is not a good choice. We learned that with Armor All in the 80's, the potential for fish eyes in paint is high.

I fought that in some way, in 1999, with both mirrors of my old 93 Explorer. Those were plastic but the surface had something in it that fouled the paint job on them, three times. I wanted to reuse them, but after the paint wrinkled the 3rd time, I went to the 95-01 mirrors.

 

[J_C]

I'm not having any problems with the grease besides the difficulty getting it off glass. Armor All and the grease I'm using (Raybestos DBL-2T) may both be silicone based but are apparently different enough... possibly due to Armor All having a carrier that evaporates so it unevenly deposits? I do wipe excess off the rubber so it's not attracting much grime.

Granted the paint had a sealant (wax) on it already but the glass didn't. Maybe that is something to try on the glass, one of those very thin film synthetic sealant products like Nufinish, but I try to avoid that stuff anywhere there are cracks/gaps/textures because it dries to a white residue. Hmm, I do have some Simoniz Diamond Something Polymer Synthetic Polish Wax Sealant Goop™ that doesn't dry nearly as white, might try that instead.

 

[CDW6212R]

Treating all of the exterior rubber is ideal, but we don't think about it enough, and what to use makes a big difference. I bought new glass for my keeper project, I was planning to wait until that's painted before worrying about it at all.