Leaking at pressure side of connection

What are we talking about? Preasure side of AC compressor pump? Power steering pump?
If AC, then possibly from a leaking AC-high preasure switch on the back of the compressor. The leak could be simply the O-ring. You simply unscrew it and install the replacement making sure the O-ring is good and in place. The switch can leak also. This part is hard to find accept at the dealer. It has a 4-wire connector on it.