Toyota Allion is a JDM only sedan and also available in Asian countries as pre-owned vehicles. This instructable is about cleaning the windshield drain holes of the specific model T 240 (2002-2005). Dirty/blocked drain lines leave rain water to stagnate in the pot holes located at either sides of the bulk head of the car. The immediate observation in such a case is dripping water in to cabin at passenger side during washing/raining. And one may hear sound of flowing water when cornering the car. In the long run it could cause pretty serious corrosion. This is a 10 minutes fix for the problem.
Although this article relates directly to 2005 Allion, this is exactly the same for Toyota Premio T240 as well. And (according to my knowledge) Toyota Corolla AE121 and 200X-2005 Toyota Avensis also should be the same as they all share the same platform.
Step 1: Open the Bonnet ...
Only tool you'll need is a flexible (yet fairly rigid), long piece of plastic tube or like. I used an old piece of door beading of about 8mm diameter. Pneumatic tube or a coaxial antenna wire should be perfect. It needs enough flexibility to pass through narrow passages while being rigid enough to push whatever the debris that may be blocking the path. (Image 1)
Once the bonnet is open, right beneath each bonnet lid hinge (or at either side of the wind shield) two pot holes are visible. If you suspect the drain lines are blocked, pour some water in. If its not getting drained immediately its blocked.
Drain channels are connected to these pot holes from the sides (or from the direction of fenders). So you will not be able to see it at all.
Step 2: Find the Drain Channel
This is the hardest task of all. Push the end of tubing against inner side wall of the pothole and slowly move it along the wall while keeping a firm hold. Give it a couple of tries and eventually the tube will find the channel. Once found, gently push the tubing down the channel. It should travel a good 40-45 centimeters. Mine traveled all the way down to the bend shown in image 2. Do not worry to push it hard if required. There should be a bend in the path and everything down there is metal.
Step 3: Flush and Finish!
When you feel like the tube has started running along fender lining, it's enough. Then pour some water with detergent into the pot hole and wiggle the tube couple of times. Then you can pull it out.
Check under the car, near the wheel arch. Soon you will start to see water dripping. Notice the third picture. There should be a good flow. If not follow previous step once more.
Give it a final rinse with fresh water and you are good to go!
If you remove the viper arms and then the wind shield trim plate you should be able to get a better access and clean entire gutter pretty well. In this case I just needed a quick fix. But when the time permits I will do it and will post a separate instructable.
Hope this helps. Thanks for reading.