2021 GT rear body leak

Blackout2021

Member
Joined
Apr 21, 2021
Messages
8
Reaction score
1
Location
Virginia
First Name
Shaun
Vehicle(s)
2021 GT
I have a 2021 Mustang GT that is having a leaking issue into the trunk. Looks like water is coming in through the body seams under the passenger corner of the rear window. I took it to the dealer they took the rear window out and seam sealed it. Picked it up today 3 days later and it is still leaking the exact same way. Has anyone else had this issue?
Advertisement

 

Tacswa

Well-Known Member
Joined
Apr 1, 2020
Messages
276
Reaction score
204
Location
Maryland
Vehicle(s)
2019 Bullitt - Shadow Black
Could the weather seal around the trunk. I had an old Crown Vic that leaked, took the back seat out, taped a hose to the roof and let the water run and just watched. Water was seeping in from a bad body joint seal/weld behind the back seat. JB weld fixed it. I would not be JB welding a 21' GT though. Maybe attach a hose the roof and watch while the trunk lid is open and see if you anything.
 

sdsteele2

Active Member
Joined
Mar 22, 2021
Messages
43
Reaction score
41
Location
Earth
Vehicle(s)
2020 Mustang GT, 2021 Explorer XLT
I am having the same issue. I have a 2020 that I bought new a few months ago. The dealer insisted it was the trunk gasket and replaced it. It’s still leaking 🤬.

I got in the trunk and had my wife spray the car with a hose. The water is leaking between what I think is the joint of the rear body, wheel tub, and the rear shelf/crossmember. I don’t see and indication that it’s leaking into the passenger area, just the trunk. I have not been able to find a good diagram of the panel assembly to see where the leak could be starting.

I have an appointment with the dealer this week but my hopes are not high.

In these photos I’m looking up from the floor of the trunk into the area below the passenger side window corner. I hat to pull the trunk liner back a bit to see both ends of the panel. Water is leaking out from both ends of the curved piece.
E07CB097-0C0C-4905-B596-13FC8EB757D8.jpeg
ADBE2BC9-17B7-43D0-8139-8B7CDA5A81CE.jpeg
 
OP
OP
Blackout2021

Blackout2021

Member
Joined
Apr 21, 2021
Messages
8
Reaction score
1
Location
Virginia
First Name
Shaun
Vehicle(s)
2021 GT
That looks like the same place I pulled all my interior in the trunk out for better visibility. My car is currently at the dealership waiting on the water specialist now. I have a video but it wo t let me put it on here.
 

sdsteele2

Active Member
Joined
Mar 22, 2021
Messages
43
Reaction score
41
Location
Earth
Vehicle(s)
2020 Mustang GT, 2021 Explorer XLT
That looks like the same place I pulled all my interior in the trunk out for better visibility. My car is currently at the dealership waiting on the water specialist now. I have a video but it wo t let me put it on here.
Sounds like we have a race to find the leak. I’ll try to respond if I find anything.
 
OP
OP
Blackout2021

Blackout2021

Member
Joined
Apr 21, 2021
Messages
8
Reaction score
1
Location
Virginia
First Name
Shaun
Vehicle(s)
2021 GT
Sounds good. On a side note my car also has a paint issue on the trunk. The black appearance pack spoiler is rubbing the paint off the trunk....has anyone had this issue? Might as well through all my problems out there 😄
 
OP
OP
Blackout2021

Blackout2021

Member
Joined
Apr 21, 2021
Messages
8
Reaction score
1
Location
Virginia
First Name
Shaun
Vehicle(s)
2021 GT
Sounds like we have a race to find the leak. I’ll try to respond if I find anything.
Got it back today. I have run the water hose to it 2 times now and no leaks. After sealing the panels when the rear window was put back in the bottom corner didn't get sealed correctly
They resealed it and now no leaks!
 

sdsteele2

Active Member
Joined
Mar 22, 2021
Messages
43
Reaction score
41
Location
Earth
Vehicle(s)
2020 Mustang GT, 2021 Explorer XLT
Congratulations!

Did they remove the glass to reseal it?

I dropped mine off after work today and they are looking at it tomorrow. After showing the tech the video I took they are suspecting the body seam as well. I didn’t think to ask if that’s a glass out repair.
 
OP
OP
Blackout2021

Blackout2021

Member
Joined
Apr 21, 2021
Messages
8
Reaction score
1
Location
Virginia
First Name
Shaun
Vehicle(s)
2021 GT
They took the glass out to do the original body seam seal. Then as a result of taking it out and putting it back they didn't get the bottom corner sealed. A bit of urethane they said and it's better than new haha.
 

Cobra Jet

Well-Known Member
Joined
Feb 12, 2015
Messages
10,178
Reaction score
12,458
Location
NJ
Vehicle(s)
2018 EB Prem. w/PP and 94 Mustang Cobra
I heard back from the dealer, looks like a body seam. They are going to remove the glass and reseal.
Well that's some good news (in a way, because they found the source - but sucks that your brand new GT has to go through such warranty work). Let us know how it turns out.
 

sdsteele2

Active Member
Joined
Mar 22, 2021
Messages
43
Reaction score
41
Location
Earth
Vehicle(s)
2020 Mustang GT, 2021 Explorer XLT
I got a call from the shop yesterday that they found the issue and repaired it. Where the spot welds are located along the side of the rear window there was rough area/burr that left a small gap in the panel seam. They wanted to let the window and seam sealant cure so I was supposed to pick up the car today.

Unfortunately when I went in I found they have managed to put several scratches in the bumper. Their glass company also over did it on sealant along the bottom of the window and the rubber strip along the bottom no longer fits because gobs of urethane sealant are in the way.

Now I get to wait for the glass company to come back out and redo the window and I get to redo it the ceramic coating on the bumper after the scratches get polished out.

Not a happy camper!
 
Advertisement

 
63 - Late Model Restoration - 1
Advertisement
Top