Ford Mustang Convertible Water Leak Problem
 

I'm in my 2nd year of ownership of a 2007 Ford Mustang Convertible. I need help understanding the design. If I understand how it is supposed to handle water, then I can figure out why mine does not.
I've determined by careful study with a garden hose, that water does not enter the trunk via the taillights, the 3rd brake light, or the trunk lid seal.
Water enters the trunk by running off the the top and then lays for a second or two along the seam between the convertible top and the body of the car and then disappears into the car.
Now, some water will enter along the sides of the car and ford has a drain hole on the side before the rear tire on either side to allow any water that happens to get in to drip out. My problem is not on the sides, or plugged drain holes.
My issue seems to be there is not watertight seal (is there supposed to be?) between the convertible top and the body beneath the rear window. The top fits pretty tightly against the body, but it is not waterproof. Water disappears after a second or two into the 'convertible top box' (my name for the metal box that holds the top) and from the box drips into trunk. After a monsoon rain, I have water everywhere. In the rear tire wheel well, in the left and right sides of the trunk, under the back seat.

Basically, anywhere you think water might be, I can find it. This can't be by design.

So, if this isn't the way it is supposed to work, then what keeps the water out? I'm thinking maybe there is a part missing.

Sorry about the severe water leaks and there is something seriously amiss. I just sold my '07 'vert and there was zero leaking. From torrential rains to snow in Alberta, there was never leaking in any climate. We took that 'vert all over the US/ Canada.
My first question is about the top itself. Is it the original top or has it been replaced? Replaced with original Haartz cloth or aftermarket vinyl?? If your top is vinyl I can offer very little assistance. Too many cheap versions, and if original Ford factory vinyl, age related issues can be endless. With the Haartz cloth the fabric can not be sopping wet or sagging bad anywhere when wet. You probably have no history with the care of the top but have you done anything to protect it yourself? RAGGTOPP or your favorite protectant MUST be used throughout the life of the cloth top. If garaged you can escape a few years of neglect but not if left outside in the elements.
Next question: Is the plastic black strip, where the fabric fits tight to the trunk area, in excellent unbroken condition? Is it warped in any way from neglect or lack of being cared for? You can't control the past but have you noticed any of these things while under your ownership?
I'm hoping your 15 year old 'vert has been cared for and garaged over the many years. No convertible top can be left in the elements for 15 years without serious issues developing, even with constant care. Leaks are a nightmare for sure so I'm hoping your situation can be remedied in some way.
If you feel like it, post some close up photos of your problem areas where the top meets the body.. Visual help is always helpful.

I'm Guessing It Got a New Top Incorrectly Installed. Just a Guess! Here are Some Ford PDF'S which May Help.

KC

Thanks. We have met the enemy and he is us. I've concluded the water is supposed to stay outside the car. I believe the entire top is not tight enough. It looks good and folds good, The rest of the story is I replaced the top in the winter when the rear window fell out of the original top. I'm YouTube certified. God help us all.

Thanks. I think you are right. LOL. Thanks for these. They're most helpful. With these, I can confirm I am not missing parts. Today's theory is that current leaking issues are not the same as whatever the original leaking issues were. I bought the car after it had sat outside for 3 years and the water in the trunk was an issue when I bought it. Then the rear window fell out. So, I replaced the top the top in the winter in an unheated garage. I had a devil of a time with it but it looks good and goes up and down just fine. So, if the water is supposed to stay outside the car, then the whole top has fit much tighter than it does. And today's conclusion is that means it probably goes back to the beginning, fastening the top to the tack strip. Well, the beginning might be the mistake in judgment that this was a job any protozoan could handle. I know now why the convertible top issues go to a upholstery shop. It's not the same as changing the water pump. It's a whole different set of skills.

No Shame on Vert Tops! It is an Art that only Experience can tame a Bit. Glad you Liked the PDF's. Not a Repair I would Touch! You are a Brave Soul To Try! :nice: Please Let Us Know How it's Coming Along!

Kc

Fools rush in, and so does water! LOL. I've got an idea. (always dangerous).

In the Recent Good Old Days we Had Google Mechanic's Before That in the Dark Ages, Shade Tree Mechanic's. At Least with Shade Tree Mechanics It was Just Hear Say Stories and Direct Witness! While There is Plenty of Good Info Out There you Have to Sift through all the Made to Get Paid Stuff Out There on Boob Tube!

Thanks For Checking in With Us Boob's!
We are Trying!

Oh and Scroll Straight Down to the Next Topic Below. Explains Testing Method.

KC

Inquiring Minds Want to Know!

KC

I didn't get to fool with it today. There's suspicious references to weather strips in the pdf3 document. Stuff like "Note the position of the weather strips and put them back in the same position". What weather strips? . There's no pictures, and I didn't have any parts left over, but I'm thinking I'm missing something and maybe was always missing something, lol, like brains. The installation video I watched had the guy pulling up the u-shaped tack strip with a huge crowbar and then pulling the staples. I'm not sure what the top mates against but it's not mating on mine. There's simply no way the top is going to keep water out of the car, so my next hair brained scheme is to add my own custom weather stripping. It might work. It won't show, No one will know its there. Did you every buy a used car and curse the dpo? (dumb previous owner). I've decided I'm the dpo getting this convertible ready for its next owner. I'll just make sure to sell it during a dry spell. Yep, top works great. See that rear window? Better than Ford's OEM design! (In my defense, one forum says its a "design issue" and you shouldn't park a 2005-2009 uphill during a rain or the trunk gets wet. . I don't believe this, but I do believe some seal wears out. Whatever causes these guys to get wet trunks is probably the same problem I've got. Does Flexseal come in white? "Wow, cool car, did you dip it? Yep, Flex sealed the who thing.

Leak Stories
 

There are some interesting leak stories out there. Back when the cars were new, one Mustang owner reports they got a 2006 convertible from Ford to replace their 2005 with a unsolvable leak problem only to discover the new 2006 from Ford had the same leak problem. Of course, no follow-up as to what became of the 2006. Another one reports that Ford "fixed" their problem by rewelding some seams. From their description, I think they were talking about seems from roof box that lead to the trunk. This might have been a fix, but I don't believe this is THE fix. Water should not be draining into the roof box (and from there into the trunk). I'd urge everyone with 2005-2009 mustang convertible to remove their spare tire. It's the lowest point in the trunk and my spare showed signs of having had been floating in water for a long time. Probably years! Much longer than I've owned the car! Luckily, the drain plug is easy to find and works well. So, when the top is raised the rear of the top is pulled up against "X" to form a watertight seal I just haven't identified exactly what "X" is. (I also think the method of prying the tack strip up using a lever and brute force as shown in several convertible top replacement videos, probably lessens the chance for achieving a water-tight seal.) I'm still designing my new "X" lol. We can rebuild him. We have the technology. We can make him better.. More watertight than before...