I hope this information helps others save some time. While there are many threads on the subject, I never found one that clearly explained front drain tubes from start to finish.

Symptom:
Last month after a rainstorm, I found about 1/2 a gallon of water under the front right floor panel.

Test:
With the front carpet/floor board removed, open the sunroof and pour water down the front drain tube.

Expected Result:
Water should exit the vehicle between the front door and the front fender. (The drain tube exits the A pillar about 1-2 inches below the sideview mirror through a hole. The hole is almost impossible to see because it is hidden by the door even when open.)

My Result:
Water poured into the floor from the A pillar. The first attachment is a picture taken with a borescope showing that the drain tube shrunk and pulled into the A pillar.

Remedy:
Replace the drain tube, Part # 124-782-07-96 "DRAIN HOSE" (about $14)
1. Remove the front headliner.
Good instructions are here: w124-headliner-replacement-photos.html
Easy way to remove/replace the rearview mirror: Youtube video
2. Thread some trimmer line through the existing tube and coax it through the hole so it is properly exiting the vehicle. This took some time but you will eventually get it to pop through. You could also try threading it through the hole and work your way up. Regardless, the goal is to get the trimmer line through the existing tube and through the exit hole.
3. Pull the old tube out from the top / sunroof area. This will leave you with the trimmer line in place.
4. Thread the new drain tube (chisel cut end first) down the pillar making sure that the trimmer line is INSIDE the tube. The trimmer line combined with the chisel cut end of the tube will help guide the tube through the exit hole. Note that i did spray the tube with a 50/50 mix of Dawn and water first so that it slid down the pillar easier.

I was surprised at how easy it was to get the tube to exit the hole. Once you have the tube through the hole keep going another 3 inches or more so that the tube can shrink and not cause the problem again. EASY RIGHT! (It took me over four hours to figure out.)

Hopefully, this information along with the pictures will help others get the job done faster than it took me. I spent hours second guessing where the tube was supposed to exit. I even went so far as to pull the wheel well lining thinking it exited there...but it doesn't. (I did find 4 inches of dirt though...)

Attached Thumbnails

       

Thanks for the great post Craig. If you have other DIY articles written or are planning to write more in the future, check out the link below. If we like the article, we'll make you a 'DIY Project Expert' and give you 10% off your next order. Let me know if this is of interest to you.

Enthusiast Tech Article Submissions - Pelican Parts


-Dmitry

Fantastic thread. Going through this crap now.