PTC Air line fittings & leaks advice

[zicc1835]

I purchased the rear bag setup from another board member who said there was a fitting leak down problem so went to local speed shop I replaced the brass Schrader valve with the 90 and a coupler and a new valve pic 1 . It leaked down over night I soap tested i tightened all the fittings cut a 1/4 inch off the airline made the cut as straight as possible and its still leaking now only from where the air line goes into quick connect suggestions / advice please