dbrobins27

I have seen seen several comments within posts about wet carpet on the passenger side. I understand that this can be related to a poor seal on a windshield or the sunroof drain. If you happen to have wet carpet and can trace the source up to the grommet/seal on the firewall this may be of help to you.

It seems the factory configuration of the drain may work will sitting still or if the truck is parked on a flat area but while moving or when on an incline it seems the condensation may drain back against that grommet on the firewall and ultimately into the cab soaking your carpet and creating the musty smell.

I noticed my carpet was soaked and the truck hasn’t seen any water in a couple of weeks either from rain or washing. I knew I needed to look elsewhere. The only source of water was the AC drain and I started researching past generations of f150’s that had similar issues. I found a TSB for the prior generation to have an elbow installed to resolve this.

Being that the truck has 15k miles I dropped it off at the dealer and let them have an opportunity to diagnose and repair. After 2 calls saying the drain functioned as intended and couldn’t find the source of the leak or water intrusion I asked them to check again after driving and to look at possibly installing the elbow as they did for the older trucks. After several back and forth calls they finally installed the elbow and the problem seems to be resolved.

If any of you are having similar problems it may be worth installing part #4M2Z-6A614-AA




AC drain in standard form.

AC drain with elbow.

RL1990

No problems with mines and I live where there is high humidity. What I do like is that it's easily accessible to stick an air hose in there to blow it out occasionally to keep it clear of debris.

If water was coming through the grommet then I would think that the grommet isn't properly seated and water tight as it should be. If this is the case then the leak may persist in heavy rain or driving in wet conditions or off road.

dbrobins27

I may be wrong but that grommet doesn’t feel waterproof or solid rubber. When mine was leaking it felt saturated. It may be slightly porous.

Regardless its a past problem in prior generations of Ford products and they install this to address the issue. If a $10 part can help or reduce the occurrence of moisture coming in by all means I’m going to do it. It can’t have any negative impacts.

koach

I have the same issue and have reached through the wheel well to ensure water drained as advertised down my arm. Unfortunately, you are correct, that foam sound insulation material does NOT serve as a seal and once water runs down the firewall, it's an easy intrusion point. On Wednesday, while attempting a half-***** repair, my dealer applied sealant instead of a drain tube (insert eye roll) and did nothing except add a deodorizer. Truck is currently sitting outside with direct Florida sunlight and carpet pulled back, but after a few hours, it's still a saturated mess.

toledoUPSguy

iTrader: (1)

Thank you for posting that part#

DJC_001

iTrader: (1)

Do you have to pull the passenger wheel well liner to add that 90 degree elbow or can you get to it from the motor bay? Seems like a good thing to do regardless if the truck has a problem or not based on your pictures.

koach

You can reach the drain and install through the wheel well. Turning the wheels hard right provides even better access.

bman91

I have a 2018 F150 Lariat with only 12K miles that also had this problem with the A/C drain. I found it about a week ago and took it to the dealer. Picked it up the same day and they said they fixed it and it was not leaking anymore. Two days later I checked it and it was still leaking. Did some research before taking the truck back in to the dealer. I found this thread and was able to pick up the part listed above. I talked to the dealer on the phone about installing this part and they first said they could not install it because it was not an Ford approved fix for my year model. Well I printed this thread out with the pictures and also the two TSBs on this issue on the two previous generation trucks. After discussing why it is leaking with my service adviser in person and showing him this thread and the two TSBs, he decided that they would install the part. He said that they had to remove the metal ring around the drain tube and then the elbow went right on. So I picked up the truck and drove it home and can say that it is no longer leaking. So for anyone else having this issue, talk to your dealer about this fix or do it yourself and it will take care of it. Funny thing is that the technician doing the work asked if he could keep the copies I brought to show how to fix it for future reference. Well worth the $15 for the part.

flynavy812

iTrader: (2)

I know you didn't install yourself, but as far as you know are you just ripping the old one out with the metal ring, and shoving the new elbow in?

dbrobins27

Be sure to check it in a couple of days. I can say without a doubt that the elbow has helped and my carpet is no longer saturated but I checked again tonight and there is the slightest bit of moisture around the grommet that is behind the elbow. It’s almost like it’s sweating.

I am working on another theory for the sweating. I noticed that there is no firewall insulation where the a/c drain discharges and that area gets pretty hot. I am wondering if the temperature differential from the engine side vs the cooler temp of the evap assembly causing sweating of the drain and that grommet absorbs and ultimately sweats or drips into the cab.

Before the elbow I had water dripping onto my weathertechs and I have mint since that since elbow installation.

Now iam wondering what engine and trim level everyone has with this problem. My nephew has a 2018 2.7 Ecoboost that is an STX. I checked his yesterday and his is as dry as can be. Also the grommet feels like it is a slightly different material. I researched part numbers today and don’t see that there has been any change recently.