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Easy fix for Mustang with wet floors.  


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Joined: 12 months ago
Posts: 3
04/09/2019 7:35 pm  

A few months ago, we had some weather in the area and one morning I started up the mustang when suddenly all my windows fogged up and you could feel the moisture in the air. Consequently, I started looking around and noticed that my passenger side floor was wet! So, I started to look around at all the drains in the car and checking for leaks, I didn’t find anything wrong until I figured out a design issue with the mustangs!
Come to find out mustangs are prone to water getting trapped in the firewall and eventually spills out into the cabin air filter box, then reaching the air vents and in it comes into the car, usually on the passenger side floor. All because of 2 rubber valves in the bottom of the firewall. But, I have an easy fix for you if this is your problem.


Is there water on the passenger floor? First let’s be sure the valves are the cause of the water. Start up the car and turn the fan on, if your windows fog up then you have moisture in the vent system. Next, take your car for a ride, turn off the radio and fan, make a few sharp quick turns (safely) and listen for the water to swash around inside the firewall. If there’s water in there you should be able to hear it. As a matter of fact, this is what led me to figuring out the issue.
If you have that much water in the car than you will need to replace the air filter and drain out the water. Furthermore, you will also need to clean the firewall drains and prevent this from happening again! Here is how to do that.
1. Open the hood and find the 4 plastic fasteners

2. Remove them but be careful not to break them.

3. Remove the plastic cowl screen.

4. Reach in the passenger side and remove/discard the cabin air filter and clean out the box of any debris.

5. Look halfway down the fire wall and find the rubber valves, these are the drains for the fire all. There will be 2 of them, one on each side.

6. Pull them straight out and clean the debris out of them. When you do this, you may want to be parked outside because the water will flow out!

7. Reinstall the rubber valves and insert the new cabin air filter.

8. Reinstall the grates and fasteners.

9. Close it all up and you are set.



In the end, once you have drained the water you will want to prevent this from happening again otherwise you risk bigger problems such as mold and electrical issues. I usually clean out the valves every couple of months and it only takes a minute or two. This way I prevent the water from overflowing because the drains are always unclogged. Moreover, you may want to do it more often if you park outside or in an area with a lot of trees! This is how to fix and prevent water on the floor of your mustang keeping it clean, mold, and trouble free. Please feel free to leave a comment if this worked for you.

This topic was modified 11 months ago by diyfixitall