Today I changed my fuel filter in my Suburban. As I am wont to do, I cut the thing open to see how it worked. I thought I would share with you what I found out.
First, let me explain and apologize. There used to be a fiber/paper filter connected to some of these metal pieces. Particularly the black burned parts. That is where the apology comes in. I had so much fun cutting the filter apart and thinking about how it has spent its whole life holding gasoline, that I just knew it would make a neat fire. So my son and I stood back and threw a flame at it. Boy was it fun. The result though is that you don’t really get to see it in all its glory. Sorry.
The first picture is the filter just cut in half. When I got it open I had cut through a paper filter that was connected at the right side (the output), but not the left side (the input). And this connection/disconnection is what makes the filter do its work.
The second picture shows the left side where the fuel comes in from the fuel tank. The little disk would be inside the can and connected to the paper filter, but not to the can. Fuel would pour into the can (through the threaded hole on top) and splash around that disk forcing all the fuel on the outside of the fiber filter (but still inside the can).
In picture three you see where the bottom of the paper filter is connected to the output hole. Gas cannot go out that hole without passing through the filter. Therein lies the mechanics and simplicity of this device.
Again, fuel passes in and is forced to the outside of the paper (or maybe a fiber of some kind) filter. But to leave the can and continue to the engine of the car, it must be sucked through the filter on its way out.
How do you know if you need to change the filter? In México you can just change it every 6 months and you are probably good. I am not sure what the normal recommendation is. If you blow into a new filter, you should be able to blow without much resistance. As the filter does its job and starts to collect gunk from your fuel, then trying to blow through it will provide quite a bit of resistance. The first time I changed my filter here I could hardly blow through it at all. I am surprised that gas even got through.
Does anyone know what the filter is made out of? Is it a paper material? Fiber of some kind? (I can Google, but I am trying to get you to comment).
You can click on any of the pictures to get a bigger version.