Guest How To: Replace Sunroof Drain Hose
January 21, 2008 – 9:05 am by Dan Volkens
Filed under Car Care, Featured, How-Tos
I have a 2001 Jetta with a sunroof, with the same problem lots of folks have noted — wet or submerged carpets after a rain.
Guest article by Volksbloggin reader George
I read various web speculations on the cause, and saw some really great pictures of the sunroof drain entry and exit points. So I poured water in the sunroof drain and sure enough water
comes out the nipples above the front door hinge. However, on the passenger side I saw some water spill out from the right side of the glove compartment and run down to the floor carpeting — a sucess for any water leak detective! I suspect this is how lots of water has been getting in my front passenger foot well, and from there somehow sloshing to the back passenger foot well.
So, I figure the drain hose is either partly disconnected or has a hole in it. I pulled back some of the interior molding next to the right side of the windshield, and found the drain hose. When I again poored some water in from the sunroof drain hole, I could feel some of it coming down the channel around the drain hose. This VW drain hose would be very time consuming to replace, involving removal of the glove box and probably much more.
My solution was simple. I went to the hardware store and bought 7 feet of 1/4 inch flexible plastic tubing to run through the existing hose from the top drain hole down through the nipple at the door hinge. To seal the hose at at the top of the drain, I bought a 1/4″ compression sleeve that slides into the hose end and has a rim to keep it from sliding all the way in. I put a washer under this rim, put some superglue on the compression sleeve to ensure it stays in the hose, and caulked under the washer before pushing it into the drain hole It fit perfectly. Don’t pull the hose tight from the botton end, just get it close. Then just push it the last half inch or so and let the caulk make the seal.
The hose went in pretty smoothly, except when it got to the nipple near the door hinge. I pryed the rubber nipple out of the body panel with a screw driver, and either at that time or earlier the original VW hose disconnected from the nipple. My new hose then pushed right through and I slid it through the nipple about 6 inches, and refit the nipple into the body. This job was surprisingly easy, and only cost $6 in supplies plus a trip to the hardware store.
Since I know this has been a big issue for dozens of VW owners on the internet, and probably hundreds or thousands who haven’t complained on the web, I took some pictures to add to the knowledge on this subject.
I should note that from my reading on this, it seems some people have wet rugs caused by problems other than sunroof drains. These other problems may include a cracked cowel outside in front of the windshield, or maybe a bad seal on a pollen filter. So, the fix above may fix your problem if you have a damaged or disconnected sunroof drain hose (or clogged drain), but there could be other problems like the two I just mentioned. I can tell you that I proved my drain hose was leaking into the car, even though a lot of water was also getting all the way through the hose and through the nipple. Maybe that’s part of the reason people think the’ve eliminated a possible problem when they haven’t. Usually, if some water is being diverted to the interior, but not all, it will not be noticable (drips within the door frame and under the rug).
After my hose installation it rained a couple of times, including a day of rain, and I see no obvious water leak. Also, after the caulk dried I poured in some water and it came rushing out perfectly. The fact that the interior hose is a little narrower than the original was no problem for effectiveness of the hose. As the water goes in the drain, gravity takes over and rapidly draws down any water in the sunroof drain bowl. This is an easy and cheap fix for a problem that can make people want to sell their car out of frustration.