Controlling the Dust

By Beau Johnston

We struggled, for years, with dust entering into the 4Runner through the rear vent.  We would vacuum out the rear of the truck after each trip to the desert.  Finally I had enough and decided tear into the truck to diagnose the problem.  

I removed the driver-side portion of the rear bumper and was amazed to find the vent flap assembly, which allows the air pressure to equalize between the vehicle interior and the exterior, was missing.  With this gone, there was a straight shot for dust to enter into the vehicle.

I ran down to our local home improvement store and purchased two types of filter media to make my own two-stage filter assembly.  I used the finer mesh register filters to create the inner portion of the filter and placed it against the interior body panel.  I then used the coarser mesh furnace filter to completely fill the void between the inner and outer panels.

After installing the filter material, I reattached the driver-side portion of the rear bumper and took the truck for a test run.  Thanks to our two-stage filter, we no longer have dust billowing into the back of our 4Runner!  The mod took less than 30 min from start to finish and only cost us around $10.  I really wish I had taken the time to determine the source of dust earlier.