Clutch line fittings

[mladen]

Me with fittings again. The fun never ends with these.

My TKX came from BPE equipped with a McLeod hydraulic throwout bearing (https://www.jegs.com/InstallationInstructions/600/673/673-1350.pdf). The fitting, according to the instructions, is 4AN. So I procured a new NPT to 4AN male fitting for my master cylinder, and a 4AN to 4AN cable (https://www.summitracing.com/parts/EAR-64191924ERL). The length seemed perfect, I drilled the hole and went to assemble it, and then I notice an issue. The instructions for AN fittings say finger tight + 1/4 turn. Well, these get finger-tight only after a few turns, and I don't think it's nearly enough for the flanges to engage. Here's what they look like when finger tight, what the male connector looks like coming from the bearing, and the female connector on the line. On hard lines, the nuts float (or whatever the correct term is) and can move down the line so the flange can engage even before you start threading it on. Not with the braided cable though. Any suggestions? Did I get the fittings wrong?

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[toadster]

looks like you have some stray braid in your fitting are you sure the threads are clean and not getting braided material when tightening?

[rich grsc]

What is an AN cable? Never heard of such a thing. My guess it the male to male adapter isn't AN x AN, but AN to male flair. Try switching it to see if the other side threads into the clutch hose.

[mladen]

Good catch on that. I'll inspect it. Looks to be inside/below the flange. When I hand tighten I'm nowhere near that, probably have a 1/4 of an inch before the flanges touch. Not sure if I just need to tighten to a specific torque.

[mladen]

What is an AN cable? Never heard of such a thing. My guess it the male to male adapter isn't AN x AN, but AN to male flair. Try switching it to see if the other side threads into the clutch hose.

Are you referring to what's coming from the throw out bearing? The instructions also say it's 4an.

[rich grsc]

I'm saying, check the male to male connector. I could be AN threads on one side and flare on the other. Take it out of the throw out bearing and try the other side to see if it threads into the hose.

[MB750]

Here's what my -3AN fitting looks like in this same application:

https://thefactoryfiveforum.com/attachment.php?attachmentid=180077&d=1676585973

https://thefactoryfiveforum.com/attachment.php?attachmentid=180076&d=1676585973

I think you've got a threads issue somewhere. Have you just tried using a wrench to get through? Lightly though, don't reef on it.

[mladen]

I tried it on the MC fitting and it threaded easily.

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Went back to the clutch line with some wrenches and managed to thread it on with about 40 ft-lb. J/k, it took just a bit more than what I could do by hand. Maybe the real problem is that my hands are weak. I'm off to install my AN cable ;)

Thank you for the help and insights as always gents!

[mikeinatlanta]

On an AN fitting "finger tight" means full seated. "Finger tight would only apply if the threads are absolutely clean and the fitting perfectly aligned. Anything on the threads or much more likely misalignment will create running torque that must be overcome to fully seat the fitting. Almost always if you can't tighten to fully seated with your fingers (even on a big fitting) it means misalignment and you need to correct to then tighten by hand.

Many many an inexperienced mechanic has damaged or had leaks by using a wrench to overcome the running torque of a slightly misaligned AN fitting that looked straight at first glance. Maybe you had a slight bur or something causing the running torque. You should break it loose and verify that you can fully seat it with your fingers, then tighten an additional 1/4 turn. If you can't fully seat with your fingers you need to figure out why now rather than dealing with the leak later.

[Jeff_J.]

I was just about to start the plumbing my TKX so this experience is really helpful. Just cruisin the conversation topics can really help prepare one for what coming. Thanks to the builders before me I avoid having to ask more questions... Great site!
Jeff_J.