[Daryl]

Does the fitting itself have the leak? Is the fitting ORB (o-ring base seal), JIC, NPT, flange seal or ORFS (o-ring face seal)? If it was indeed an o-ring, check to ensure that doesn't display damage from installation. What is the normal operating and maximum allowable pressure of the system? There is an extremely large difference between some thing that operates at 2800 and 3500 psi. If the failure is from over-pressure, verify the other components are functioning correctly. Let me know as hydraulics are something that HAS to be perfect. Make sure that if you only need to replace the o-ring(s), don't cheap out... the difference between a one dollar o-ring and a three dollar o-ring is about fourty gallons of oil.