When I first got out of college, the company I worked for built custom machines for IBM. Most of the assemblers were toolmakers with many years of experience. There were a few "blind monkeys", as can occur anywhere. IBM has a standard which forbids the use of teflon tape on fittings for just the reason described. We either had to use tube based sealent (SWAK),
or buy fittings with sealant already applied.
I just got an FEL for my B2400 about a month ago. The first time I removed and installed the loader, one of the quick-couplers started to leak. I tried reseating it the the leak persisted. I called the dealer who thought it was probably a o-ring. As he was swamped with work, I offered to remove the fittings and just do a swap. I did have a bit of a hard time getting the hose fitting off. The flare wrench I have would not fit, and the open end wrench rounded the hose nut /forums/images/graemlins/blush.gif.
Anyway, after a little heat, the swap was complete and the leak was gone. /forums/images/graemlins/cool.gif