Put a Mustang II power rack and pinion on my 60 F100. I cannot get the high pressure hose to stop leaking at the fitting on the rack (9/16 x 6an). The fitting came with an o-ring. I tightened it to 10 ft lbs and I didn't use tape as per the instructions that came with the rack. There must be a trick to this. It's driving me crazy! What about using Loctite 545? A BFH? Please help.
There are a number of different styles of fittings used on the racks. I think the type you have uses a small O ring on the end of the tube and a small nylon type seal on the fitting its self. Have you tried talking to your rack supplier?. You should not use or need any type of sealant on this conection. A pic of the fitting you are using would be a big help.