I am a proud new owner of a cat 30 which I just launched this week. Unfortunately the stuffing box is leaking way more than it should be. I know a lot of people use adjustable wrenches, but does any one know the nut sizes so I could use an open ended wrench. The nuts look pretty corroded and will take some torque/pb blaster to get free so I prefer to use a traditional open ended wrench. Is this the wrong approach.