When I took my fuel tank compression fittings apart for the return line and the sump tank breather I found (leaky) brass compression fittings.
I ordered what I thought were the right replacements from SNG (and they finally arrived after a solid month of backorder) for those two fittings/lines. What came is in this photo. The short two ended piece (for the return line) has the brass compression fitting (with ferrule) I expected for the connection to the bulkhead but on the other side is a green viton piece and barb like ridge behind it. This different type is also on the tank end of the breather hose.
Question: can these two types of fitting be used interchangeably or not? Last thing I want is to install new pieces and put it all back together just for it to leak again but at the same time these were the parts I could find (and they said they fit my 89 and the new reproduction tank I bought from SNG as well). What’s the theory behind the vitons and the ridge/barb behind them?
Are the brass and viton different styles but interchangeable?