[UPDATED 5/5/2019, 7/18/2019]
The drain tubes for the convertible top well (allows rain/car wash water to drain out the underside of the vehicle so that it won’t otherwise collect and eventually seek it’s way under the carpeting behind your seats or in the trunk) in our 124 Spiders (and the ND MX-5) are each protected by a dual filter system
- upper – the filter cap screen (as shown in the photo above) and
- lower – an underlying foam filter
so that the tubes should never need to be snaked out, unlike the unfiltered tubes in the previous generation (NC) Miatas. One potential issue that Mazda may have forgotten about with the foam filter is that a water-logged “sponge” could freeze in the cold winters, which can result in thawing snow on the vehicle not being able to exit out the drain tubes as intended. It may actually be a good idea to remove the foam filter for the winter season, especially if the vehicle is left outside in the snow.
Although the owner’s manual recommends cleaning these filters (they are symmetrically placed on both sides of the vehicle) annually, as the owner, you should be familiar with how much debris (leaves, pine needles, bugs, etc) your vehicle has been exposed to, and only address these filters when you suspect that they might actually need cleaning.
In my case, I’ve never parked my car underneath a messy tree, and I park the vehicle in my garage nightly, so I am confident that for now, this difficult maneuver would be a waste of time.
Karatou-Oyaji produced a YouTube video that although is in Japanese, shows how to access the filters for removal and cleaning without removing any panels. I don’t know if he was viewing his camera while locating the filter for removal and re-installation, but I like djwhiplash2001‘s comment:
When I do this, I’m going to stick a GoPro to my rear window and view it on my phone – that way, I can see what I’m doing (hopefully).
Raptor5244 offered this advice (which is demonstrated in the photo above) in the Miata forum:
I found it easier to get to the drain filters if I stood outside the car and reached my arm down there vs. sitting in the seat. The trick to getting them out is to use you index finger front knuckle pressed on the tab, and then use your thumb and middle finger to pinch/grab the filter [foam-covered pull tab, (shown in the photo below)] to wiggle it free.
It took are a few tries but figured out a way that works best for me. To orient where they are, look through the back window and look for the foam around the base of the filter.
yorksboy also provided me some feedback and photos on 5/5/2019. In order to better view the drain filter placement for some photos, he removed the cover behind his RHD driver’s roll bar:
It seems like Mazda should have incorporated some kind of texture on the release tab surfaces.
I have discovered another video posted by ProfRobBob that shows a much easier method of accessing the drain filters , by removing a trim panel hiding the seat belt retracters. This results in being able to see the filters, as shown in the photos directly above. Just be aware that he doesn’t check the foam filter element (at least not in this segment of the video), and that is the most important part of this process. I would have avoided this method, as do others, had I not seen the video, thinking it would be more tedious than it actually is.
Here is the procedure from Mazda’s Service Manual [with additional edited comments suggested by James Hebert 10/24/2017 and yorksboy 5/5/2019]:
Drain Cover Cleaning
Clean the drain cover using the following procedure.
1. [Open the top about 1 foot away from the windshield header (as shown in the diagram), and standing alongside the vehicle facing forwards], reach in behind the bow to locate the filter cap [(you are working entirely by feel, as you cannot see the filter while reaching for it):
- LHD driver’s side cover: you need to use your right arm
- LHD passenger side: you need to use your left arm
2. The photo of the passenger side/right hand filter below ⇓ shows the referenced release tab in the upper left, but what is not seen in Mazda’s diagram is the foam covered “pull tab”. While grasping the pull tab,] press the release tab in the direction of arrow (1) shown in the figure, move the upper drain filter in the direction of arrow (2) and remove it.
2. Remove the lower [foam] drain filter.
3. Clean the removed parts. Hopefully it doesn’t look quite as dirty as littletone101’s…
4. Install in the reverse order of removal [and jiggle the filter cap, to insure that it is securely latched. Tobias adds:
For re-assembly, I found that just jiggling the cage wasn’t enough. Mine even made a nice clicking sound but still wasn’t properly secured. Pressing the cage’s release tab towards the outside of the vehicle is what did the trick for me.]