Urgent TOURIST visa question!

Yes, as long as you haven't used up all of your 180 days in the "rolling" year you can re-enter Brazil with no problems. You might have to come up with some interesting excuse why you're returning for a few days only, but then again they may not even ask. Just remember in calculating your days you must count the day you entered Brazil and the day of your departure as full days, add them all up and subtract from 180, that's how many days you're entitled to.

Hey, thanks so much man!
I figured that would be what the deal was - I already crafted a pretty convincing narrative as to why I'm only going to be there for a few days. Thanks for the advice.
Now with two people telling me it's ok I can be at ease.

Yeah, you can be at ease until the visa expires while you're here. Then you will have to be looking over your shoulder all the time.

Just a word to the wise, here in Brazil if you happen to be anywhere near something bad that happens (wrong place / wrong time and all that neat stuff) and the cops show up on the scene it's routine that they stop EVERYBODY not just those involved. In Brazil you must identify yourself when a police officer demands you to, or you get arrested on the spot.

The law also requires everyone, Brazilian and foreigner alike to carry identification documents and foreigners must carry their travel documents (or at least certified copies of them) at all times. If you're asked for ID and you're a foreigner on an expired visa the game is over, next stop the Superintendência Regional da Policia Federal - Departamento de Estrangeiros.

Also, you really can't let anybody (especially a Brazilian) know you're visa isn't current. Some of them have the crazy idea that if they turn you in they'll get some kind of reward (not true) and they don't seem to know that even for the Federal Police visa overstays aren't taken very seriously, other than the fine.... that they love.