The caps are a real weak point on the Traxxas shocks, I've popped mine a lot and they're like Pringles, once you pop you can't stop. You can either get another set of the stock ones for around $20 on ebay and replace the caps with the aluminum ones but by time you do that, you're just under the cost of some Big Bores from a chop shop. You can get by with just screwing the cap back on, make sure the diaphragm didn't fall out, refill and tighten it down nice and snug.
---------- Post added at 11:15 PM ---------- Previous post was at 11:13 PM ----------
If you're into moding, you could throw some 1/8 scale buggy shocks on it. I can't remember what buggy but I've read a few threads on it and they say the handling is much better and the shocks can take a real beating.