A little water in your car can quickly turn into a big problem. First, it’s just annoying: dampness in the passenger compartment, some mildew on the headliner, maybe. Then, if not addressed soon enough, that water has found its way into electrical systems, and colonies of mold has developed in the carpeting.
Suddenly what was once a minor maintenance problem is now a thousand dollar repair cost. Many times this begins with a plugged sunroof drain tube. These small tubes comes from the corner of the roof and extend downward through the rocker panel or door sill.
While built to manage light rainwater, these drains is also prone to collecting mud, pine needles, and the tacky goo of summer road trips. Cleaning them out is one of those projects that sounds overwhelming until you know how it works. Once you do, it’s a simple process that will keep your interior free from slow rot.
Simple Steps To Clear Clogged Sunroof Drains
Why Sunroof Drains Clog
The best option are to use compressed air to blow out these drains. If you do it right, it’s easy, quick, and quite gentle on the tubing (it’s all plastic). How do I know?
Because I’ve done this before many times! The trick is to control how much air you’re pushing out. You shouldn’t do that not just because you don’t want a hole in your plumbing, but also because you’re basically trying to push a soft rubber plug out.
Most online instructions will tell you to blast it with high pressure. Don’t do that. That stuff is usually pushed into tight areas behind your trim panels and the tubing can be pretty flimsy.
Blow too hard and you’ll have to take half your door apart to fix it. What you want is a nice, steady stream at a moderate level. It should be enough to dislodge the junk but not so hard that you wreck the plumbing in the process.
Gather Cleaning Tools
Brute force isn’t going to get you far here. It’s all about technique. There are only a couple things necessary to do this task.
First, an air tank, either a regular compressor or even one of those little tire inflators with a gauge would work fine. Second, you need some clear tubing to plug the hole in the tube. Something like this available at your local hardware store works great.
Not only does it provide a direct route into the tube to the drain, but it allows you to visually monitor for airflow. As a backup, if the tubing won’t slide down into place easy, you may need to use a longer, more flexible wire to poke the obstruction farther back into place. Then, add the air.
The air is what matters most. And you’ll want something that regulates the PSI so you have control over the force. Because high pressure is bad here.
Too much air can pulls the tubing out of place where it’s mounted on the inside of car body. Something in the 30-50 psi range is all that’s needed. It is enough to dislodge wet leaves, but nothing too crazy.
Locate the Drain Inlet
The first thing to locate physically is the drain inlet. On most vehicles this will be located in one of front corners of the sunroof frame. It’s typically surrounded by a rubber gutter which runs along the outside edge of the glass.
Inserting a finger into the gutter, look up and you’ll find a little hole, likely capped with either a plug or some sort of mesh screen. First, clear away whatever is on top of the gutter. Next, take a piece of wire or other small brush and clean the area next to the hole.
Insert Tubing and Seal
Now if you can see the hole, you’re good to go… just bring in the air! If there’s a plug hiding the hole, carefully work it free. Take care not to knock the plug down the tube; that would be a pain to get back out.
Have a catch bowl handy for small parts like this. Doing so will make sure that the air pressure goes directly into the space it has to fill, as opposed to shooting up under the rubber seal. Feed your plastic tubing through the drain hole.
Make sure that you get a good seal. Air need to flow down the tube and not out the sides. Push it in as far as it will go without forcing it.
The tube should slip right up through the drain hole. Stop if you feel resistance. Don’t force it.
This may cause the internal drain line to kink, creating a blockage. After seating the tubing, hook up your air source. Adjust your regulator downward to about thirty PSI.
Apply Compressed Air
Give it a quick shot of air. You should hear it “whoosh” out the other end. Water and/or debris may also spew out under the door toward the wheel well.
Have someone standing by at the outlet spot or lay a towel down to soak up the mess. Seeing the blockage come out of the vehicle is quite satisfying. When you take a shot at it, give it a few bursts.
Maybe 30-50 psi max. You don’t want to go over 50. Then again with a quick burst. Don’t hold the trigger down.
I know, this is hard, because sometimes that’s all that works. But you run the risk of building up pressure behind the blockage and doing more harm then good. Use just little quick puffs.
That will help loosen the blockage, like when dried leaves or mud get packed down. It’ll help loosen it up. So, you haven’t cleared it yet?
Good. Check your lines. Is your tubing tight against the drain inlet?
The tubing shouldn’t be loose, or it’ll just blow air into the sunroof channel (which doesn’t help anything) and possibly force some water back in the cabin. Also, listen for what your car is telling you. Remember: patience is crucial.
Don’t rush it. Don’t make any mistakes. Once cleared, the next smart move would be to run some water through it.
Verify Flow with Water
Use the same drain inlet and pour a small amount of water in. Watch how it looks as it comes out at the bottom. It should come out smoothly without bubbles or other obstructions.
That means the pathway has been entirely opened and there are no new blockages farther along the line. It will also wash away any remaining free-floating junk that may have been loosened by the air but not removed. If it goes slow, do the air thing again.
Debris can lodge in corners. Air pressure combined with flowing water is best for a really good clean. You know everything’s working right.
Regular Maintenance Tips
These are not emergencies, they’re preventable if you maintain them regularly. If you live in an area where there’s lots of fall leaves or pollen, check your sunroof drains every few months. Clearing the tubes requires nothing more than a quick air blast.
No big deal. It takes five minutes and prevents thousands of dollars in damage. No problem…
Just five minutes and you won’t spend thousands of dollars on repairs. Change your oil, right? That’s how you should view this.
A tiny bit of work for the bigger system to run smoothly. You’ll drive around feeling fresh and dry. Then, when you have water puddling up on your sunroof next time, you’ll remember: The answer isn’t as complicated as you’d think.
Just a lot of love and a little pressure.
