NodeJS/Express, Receiving pdf in response body - node.js

Question

I have a node instance using express. It makes call to a JAVA backend. When I receive the response I check if there is a content-disposition header and react accordingly with the type of file.
The content of the response.body is the pdf in binary content. With content-type header "application/pdf;charset=UTF-8". I also receive a Content-Transfer-Encoding header set to binary.
If I call my JAVA backend directly from a REST client, everything is fine and I can view the raw body or download the file.
If I go with node, the PDF is blank. But has the correct number of pages.
Here's how I forward the respond to the frontend.
res.status(response.statusCode).set('content-disposition', response.contentDisposition).set('Content-Type', response.contentType).send(response.body);
Is it possible Express is converting it to some default encoding before I can even have access to the response ?
All I want to do is take the body response from my java backend ajust the headers and send it back to the frontend.
Thank you
EDIT
This is the options I pass to my request function
method=GET, user=username, pass=password, uri=http://appsjava-veo01.hostname:8081/VEO/r/pap/pap5001/produire/311, Content-Type=*/*, Accept=*/*
Calling my http handler, and in the callback sending back the response
httpRequest(options, req, res, function(err, response){
if (err){
return next(err);
}else{
if (response.jsonResponse){
res.status(response.statusCode).set('Content-Type', 'application/json').send(response.jsonResponse);
}else{
if (response.contentDisposition){
res.status(response.statusCode).set('Content-Disposition', response.contentDisposition).set('Content-Type', response.contentType).send(response.messageHtml);
}else {
res.status(response.statusCode).set('Content-Type', 'application/json').send(JSON.stringify({
success: response.success,
message: response.message,
messageHtml: response.messageHtml,
dateJour: response.dateJour,
usager: response.usager
}));
}
}
}
});
var httpRequest = function(options, req, res, callback) {
var errorMsg, dateJour;
ASQ(function (done) {
request(options, function (error, response) {
if (!response) {
done.fail(error);
} else {
done(response);
}
});
})
.then(function (done, response) {
var bodyResponse,
httpResponse,
jsonResponse,
contentDisposition = response.headers['content-disposition'],
usager = (req.session.cas) ? req.session.cas.user : 'nocas';
dateJour = new Date().toJSON();
//Validation et aiguillage selon les status code http
if (response.statusCode === 401) {
req.session.pt = '';
httpResponse = {
'statusCode': 401,
'success': false,
'message': '401 - Authorization requise',
'messageHtml': response.body,
'dateJour': dateJour,
'jsonResponse': null,
'usager': usager
};
return callback(null, httpResponse);
} else if (response.statusCode.toString().charAt(0) === '2' || response.statusCode === 406 || response.statusCode === 428) {
if (contentDisposition) {
var contentType = utils.extractContentType(contentDisposition);
httpResponse = {
'statusCode': response.statusCode,
'success': true,
'message': 'Téléchargement du fichier',
'messageHtml': response.body,
'dateJour': dateJour,
'jsonResponse': null,
'contentDisposition': contentDisposition,
'contentType': contentType,
'usager': usager
};
return callback(null, httpResponse);
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