Needs to be smoother, those lines are too straight, and the dirt looks good, maybe try it ingame first
I'd say it looks a bit too pixel-y, especially around the line. did you apply a noise filter? If so, I wouldn't. Defects should look done by hand, as if the brush slipped, or something has hit it and damaged it. Of course, how it should look also depends on where you are intending it to go. As in, indoors (spytech, farm, or industrial) or as an exterior texture. EDIT: one more thing, The dirt should be more obvious and start from the bottom.
I would also make the bottom part a bit darker and without a red tint, the colors seem all too similar to me.
In-Line with what Grazr said, you should generally try to have visible paintstrokes in TF2 textures, if you have a look at some already in the game, you should notice a lot of them have very visible brushstrokes still present. Also: What colours are you basing this off? Guesswork, or some other texture?
I'm not at home or I'd point to what I'm talking talking. On the red stripe you have "stains". however because the texture will be repeating those stains will look terrible ingame due to the same "stain" shown every 4 feet. I would remove them from the line.