Power Steering to steering gear box fitting leaks.

I replace the original power steering gearbox with a remanufactured one. I don't think they were always in the fittings when I took it apart it's awfully hard and much like a brake line. I have tried putting the O-rings in that came with the new gearbox and it leaks. On the low pressure side I went without an o-ring and it quit leaking? When I don't put in the O-ring on the high-pressure side it weeps but with an o-ring it leaks more? The fitting only calls for 25 foot pounds of torque.