Since no one actually has given an answer to this question yet, i'll give it a go, since i am majoring history at a brazilian university that has a very big tradition on studying the coup and the dictatorship.
The united states had a direct interest in the ways the political situation in Brazil was shaping up. On the months leading up to the coup, the Kennedy administration. Some cables, made available somewhat recently document an exchange between Kennedy and the residing embassator in Brazil, when they agree on financing, with 3 million dollars (a sizeable amount for the time, and a monstrous amount for a small brazilian economy) opposing parties, going on a destablization campaign agains João Goulart's government.
US's support did not stop there: Once the conspiration was fully developed and the coup was arranged, the United States prepared an invasion plan to help the coup, in case it found resistance from the legalist branches of the army and government. You will find it online and on bibliography as Operation Brother Sam. It was actually a big movement, with part of the caribbean fleet and a Forrestal class carrier.
You got to remember that, while the United States gave support to the invasion based on their Foregin policy doctrine, the coup is considered inside brazilian academia as a Civil-Military coup. Whether or not they were manipulated the fact is that on the months leading up to the coup, the entire media, the Order of the Lawyers of Brazil, The church, the middle class and the upper echleon of society all supported the coup. With the action being taken by the military.
In short: The US did lend support to the conspiracy and to the coup itself, but in no way in the same intensity as we saw in the case of Chile. Just as much of the fault for the dictatorship falls in the hands of the brazilian civil society, that not only turned a blind eye to the ascension of the military to power, but actively applauded such acts.
Much of my answer is based on the work of my teacher, Carlos Fico, and one of his (many) books on the subject: O grande irmão: da Operação Brother Sam aos Anos de Chumbo O Governo dos Estados Unidos e a Ditadura Militar Brasileira (The big brother: from the Brother Sam operation to the Lead Years. The government of the united states and the brazilian military dictatorship.)
Recently, many archives regarding the involvement of the US in the Coup have been released to the public. Here is a link with the files in question, as provided by /u/Lard_Baron when I asked this question some time ago. Also, there are two posts with relatively long answers. Here and here.
~~/beginrant Also, I would like to express my distaste at something I've seen in this subreddit. Questions that are considered "uninteresting" to the userbase of this subreddit rarely get upvoted. At this moment, this post has 4 upvotes and 2 downvotes, which is unacceptable, since this question is just as valid as any other one, but since it's not about "fun" themes like Medieval Europe or WWI-WWII and Christianity/Islam it won't receive attention. Also, I've seen a tendency of questions regarding shady actions of the north american government being downvoted because, after all, ~60% of redditors are North American, and some feel directly hurt by such insinuations. I don't get it./endrant~~
Edit: I just noticed I linked to a post made by OP himself. And the post took off. I'm more relieved now.
Was João Goulart leaning toward the Soviets or communism?
This would explain why the middle and upper class supported the coup, they did not want to lose their property. It would also explain US involvement.