Five-8

Finally got the fuel lines to let go, so i can install GB's replacements.My question here is:

Is the threaded sleeve on the fuel line supposed to be free of the line itself, i was expecting the threads to be integral to the line itself, i don't see any damage so i believe this is correct...just wanted to confirm please.

For these lines, plus the other hard lines atop the engine,
A)Anti-seize?
B)Threadlocker?
C)Nothing?
D)Something Else?

Thanks as Always!

Cheers,

dr bob

The threaded sleeve (nut) needs to stay loose on the line so you can tighten it without risk of galling or otherwise deforming the metal while tightening or loosening.

Traditionally, no sealant is used on these connections. The 'sealing' is done where the cone on one side mates with the bubble on the other side, metal to metal. That said, the fittings are too often over-tightened, usually by someone trying to solve a seepage issue. When that happens, the metal is deformed, and sometimes galled as your picture of the lower line shows. Of course, the connection is usually overtightened even more, as you try to get the distorted and galled metal to seal against the fuel pressure. Some here have had success using Loctite 574 (IIRC...) anaerobic sealant just on the mating metal faces of the joint. I usually put anti-sieze on the threads regardless, but it's virtually impossible to use both without risking contamination of any sealant added to the joint face.

Like all hydraulic work, there are severe penalties for contamination. The lines you show need to be ever so carefully cleaned at least an inch or two back from the connection. The cleaned threaded nut comes up onto the cleaned section of line, and a loop of masking tape goes around the line behind to keep the nut from sliding back down into the dirty part. Then clean thoroughly again. All it takes is one tiny bit of crud, slime, debris, gravel, whatever, to keep the sealing faces from meeting up correctly. Then you get a leak, tighten to try and stop the leak, etc., until the metal sealing faces are so chewed up that you need to use... ad mausoleum.

Five-8

Thanks Dr Bob once again.

I shall inspect the other connections as well and proceed accordingly.I appreciate the detail you have provided.

Cheers,

M. Requin

>"... ad mausoleum."

Thank you, I'm stealing that...

dr bob

"Until it's completely dead and buried", in my worst grammer school Latin.


And of course there's a tiny fee for recycling stuff like this.