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2015-2023 Ford Mustang Water Leak Fix

Created by Jay Walling
Date Created: 3/24/2022
Last Updated: 1/25/2023

Within this article, we will cover a common issue with the S550 chassis. Inside the door/fender area, there is a common water leak that needs to be addressed and we will show you how to fix this!

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FOLLOW: 2015 mustang , tech guide , installation

2015-2022 S550 A-Pillar/Door Jamb Water Leak Fix - 2015-2022 S550 A-Pillar/Door Jamb Water Leak Fix

The S550 Mustang is one of the best platforms Ford has ever produced. That does not mean they do not have some drawbacks that need addressing. After washing our 2015 Triple Yellow Mustang GT we have here at the shop, we noticed a fair amount of water pooled on the driver's side floorboard. Since this was located on this side of the vehicle, we knew we could eliminate the heater core as a possible culprit.

After further investigation, we noticed an open hole in the A-pillar/door jamb. After a quick spray down in this spot, we had found that this was where the water was coming into the car. Ford used a small round decal to cover this hole from the factory. Over the years, this decal had fallen off. From the amount of water that was allowed to pass in, this leak over time could have ruined the interior carpet, or worse, caused rust or possible structural damage to the floor pan.

After a few measurements and test fits, we were able to find the properly sized grommet to seal off this hole. This part number is HDW-21110A and can be found through our website.

Installation of this part can be tricky due to the tight area; follow along, and we will show you the steps involved to complete this task.

The part number needed for this fix will be HDW-21110A.

Tools Needed

  • Interior Trim Tool Set
  • General cleaning supplies

A-Pillar Door Jam Rubber Plug Replacement Steps

  1. To begin the installation, you will need to open either the driver's or passenger's door to locate this hole. This is inline with the exterior fender badge if equipped on the S550 fender.
  2. 2015-2022 S550 Fender Area Water Leak Fix.  - 2015-2022 S550 Fender Area Water Leak Fix.

  3. Next, if the decal is still in place, reach in between the door and the fender to remove this, and carefully clean any residue off from the hole.
  4. 2015-2022 S550 Fender Area Water Leak Fix.  - 2015-2022 S550 Fender Area Water Leak Fix.

  5. Now, place the grommet over the hole and push firmly against it to seat this into the hole. You can use a small trim tool here if you cannot reach this by hand. A small dab of silicone can also be used here to add to the protection of any future leaks.
  6. 2015-2022 S550 Fender Area Water Leak Fix.  - 2015-2022 S550 Fender Area Water Leak Fix.

  7. Now you can check over your work and you are all done!
  8. 2015-2022 S550 Fender Area Water Leak Fix.  - 2015-2022 S550 Fender Area Water Leak Fix.

    Installation Conclusion

    This may seem like a simple task, but it is a needed fix for all S550 owners. Even if your car does not have a leak, this is a great preventative measure to ensure you do not run into this problem down the road.

Thumbnail image of the author of this article, Jay Walling.

About the Author

Jay has written content for Late Model Restoration for over 10 years, producing over 120 articles. Jay has an extensive 25-plus-year background in automotive and is a certified Ford Technician. Read more...