Is the word caminhão the same in Brazilian and European Portuguese?

No.

The word is different in terms of spelling and typical usage. In Brazilian Portuguese, the standard term is caminhão, whereas in Continental Portuguese, the standard term is camião. While the meaning remains the same, the spelling changes, and the way the action of operating the vehicle is described also differs (for example, Brazilians typically use the verb dirigir, while Portuguese people more commonly use conduzir).

Brazilian Portuguese

1. O caminhão de lixo passou cedo hoje. (The garbage truck passed early today.)
2. Ele trabalha dirigindo um caminhão. (He works driving a truck.)
3. A carga está dentro do caminhão. (The cargo is inside the truck.)
4. Aquele caminhão é muito grande! (That truck is very big!)
5. O motorista do caminhão parou no posto. (The truck driver stopped at the gas station.)

Continental Portuguese

1. O camião do lixo passou cedo hoje. (The rubbish lorry passed early today.)
2. Ele trabalha a conduzir um camião. (He works driving a lorry.)
3. A carga está dentro do camião. (The cargo is inside the lorry.)
4. Aquele camião é muito grande! (That lorry is very big!)
5. O motorista do camião parou no posto. (The lorry driver stopped at the gas station.)