AN Compression Fittings

[gbranham]

I have some of Earl's -6AN compression fittings to attach to my 3/8" hard fuel lines. Any tips or tricks, or just run 'em on?

Thanks,

Greg

[JohnK]

Did they not come with any instructions? The Let-Lok compression fittings that Breeze sells came with pretty specific and detailed installation instructions.

[gbranham]

Did they not come with any instructions? The Let-Lok compression fittings that Breeze sells came with pretty specific and detailed installation instructions.

They did not. Just the two halves of the fitting, and the brass 'olive' bit that goes in the middle. I assume there's really only one way to do it, but wanted to be sure.

[JohnK]

I'd reach out to them to confirm. Let-Lok has pretty specific instruction on how much to tighten the fitting, which varies by AN size. "Good enough" might be OK, or it might not be.

[Mike.Bray]

I used them on my fuel lines. Main thing is to get the tube set to the correct depth in the fitting. I installed the fitting on the tube then attached the fitting to the bulkhead fitting to set everything. Then just tighten it up. It will compress the ferrule to the tube and you're done. They work just like the brass fittings you get for copper tubing at Ace Hardware.

https://www.holley.com/products/plumbing_an_fittings_and_hose/hardline/compression_adapters/parts/AT165106ERL

[MPTech]

I bought 3/8, -6 fittings from Hot Rod Fuel Hose for my fuel system.
They were a BEAR to get on!! (Thanks again Rich!) We even used a tool to install them, but still VERY difficult.
They are good now, but I wouldn't advise them unless there is a good trick.
I bought the stainless steel fittings and line for my PS a couple years ago and it was much easier to assemble, but be prepared to get SS wire stuck in your finger tips! Ouch. If you can get access to a braided hose cutter, even better.
Lots of YouTube videos to help here. Wrap the end to cut with masking tape (1 layer), clean cut is the key, leave the tape on and install the fittings. Remove tape after installation.

Good luck!

[gbranham]

I bought 3/8, -6 fittings from Hot Rod Fuel Hose for my fuel system.
They were a BEAR to get on!! (Thanks again Rich!) We even used a tool to install them, but still VERY difficult.
They are good now, but I wouldn't advise them unless there is a good trick.
I bought the stainless steel fittings and line for my PS a couple years ago and it was much easier to assemble, but be prepared to get SS wire stuck in your finger tips! Ouch. If you can get access to a braided hose cutter, even better.
Lots of YouTube videos to help here. Wrap the end to cut with masking tape (1 layer), clean cut is the key, leave the tape on and install the fittings. Remove tape after installation.

Good luck!

Thanks. I'm talking about 3/8" hard line to -6AN compression fittings, not SS braided hose.

[Mike.Bray]

I bought 3/8, -6 fittings from Hot Rod Fuel Hose for my fuel system.
They were a BEAR to get on!! (Thanks again Rich!) We even used a tool to install them, but still VERY difficult.

I used the Hot Rod Fuel Hose PTFE fittings and hose for my fuel system. I didn't find it all that difficult to assemble, here's my step by step:

I wrapped the hose with duct tape and cut it with an abrasive cutoff wheel.

Next I used a tapered punch to get the PTFE liner back round.

I installed the nut over the hose.

I used a small screwdriver to carefully pry the outer braid away from the PTFE liner.

Install the compression ferrule. I used a small rawhide mallet to tap it all the way on.

Lubricate the fitting and threads with light oil and insert it into the hose. I use a socket & ratchet to apply pressure while turning to get the threads started.

Tighten.

Oh yeah, the real trick to assembling these things? Invest in these (https://www.holley.com/products/plumbing_an_fittings_and_hose/plumbing_tools/vice_jaws/parts/1004ERL). I can assemble a fitting onto a hose in less than two minutes using the vice jaws to hold the hose.

[Papa]

Off topic, but for braided SS lines, this tool makes assembly a breeze!

Koul Tools 6 AN Hose Assembly Tool Single -6 https://a.co/d/ikewdTM

They come in sizes for the hose you're using.


https://youtu.be/kAllt-AnF8o?si=5CL3FXCVDEe78ygZ

[Fman]

+1 on lubing the threads, if you don't do this it will not tighten down easily and you can damage the AN fitting. Hopefully you are also using PTFE fuel lines.

[rich grsc]

I used the Hot Rod Fuel Hose PTFE fittings and hose for my fuel system. I didn't find it all that difficult to assemble, here's my step by step:

I wrapped the hose with duct tape and cut it with an abrasive cutoff wheel.

Next I used a tapered punch to get the PTFE liner back round.

I installed the nut over the hose.

I used a small screwdriver to carefully pry the outer braid away from the PTFE liner.

Install the compression ferrule. I used a small rawhide mallet to tap it all the way on.

Lubricate the fitting and threads with light oil and insert it into the hose. I use a socket & ratchet to apply pressure while turning to get the threads started.

Tighten.

Oh yeah, the real trick to assembling these things? Invest in these (https://www.holley.com/products/plumbing_an_fittings_and_hose/plumbing_tools/vice_jaws/parts/1004ERL). I can assemble a fitting onto a hose in less than two minutes using the vice jaws to hold the hose.

Mike, I have to think the fittings Mark got had a manufacturing defect, or they shipped the wrong tube nuts for the type of hose. I have made up this type of fitting before with no trouble. It took over 2 hrs to make 8 hose ends. You just could not fit the nut over the hose after you cut it, all it would do is push the outer cover back off the inner hose. We even used the assembly tool like Papa shows. I won't ever buy from them.

[F500guy]

Most hard line compression fittings require 3/4 to 5/4 turn past snug to get the compression sleeve 'olive' to compress on the tube. Key is to ensure the tube end is square and de-burred and fully inserted, and this will result in slight deformation of the tube so the sleeve will stay put and the tube will not slide back. Lots of info on interweb.

[MPTech]

Thanks. I'm talking about 3/8" hard line to -6AN compression fittings, not SS braided hose.

Sorry, didn't mean to take this off-topic. I did a hardline AN fitting on my old fuel line and it went very easy. No special tools required! Just be careful not to scratch them, it's very easy to do.

[Mike.Bray]

Mike, I have to think the fittings Mark got had a manufacturing defect, or they shipped the wrong tube nuts for the type of hose. I have made up this type of fitting before with no trouble. It took over 2 hrs to make 8 hose ends. You just could not fit the nut over the hose after you cut it, all it would do is push the outer cover back off the inner hose. We even used the assembly tool like Papa shows. I won't ever buy from them.

I've used a lot of AN hose and fittings over the years; Russell, Aeroquip, Earl's, and a few I can't remember. I used Hot Rod Fuel Hose for my FFR project and was very impressed with the service, quality, and price. I didn't have any issues at all with assembly and would use them again in a heartbeat.

I gather from talking to them they are a smaller privately owned company. I needed a somewhat special fitting for my power steering that they were out of stock and they jumped through hoops to get it for me.

I suspect as you said there was either a defect or you got the wrong fittings. Did you talk to them Rich? Like I said I found their customer service to be very good.

[rich grsc]

Mike, I didn't call them. I was helping Mark (MPTech), don't remember if he called them or not.

[phileas_fogg]

Greg,

I used Earl's fittings on all my fuel lines. I had to use tube nuts to adapt my 1/4" and 5/16" hard lines to -6AN. I don't recall any drama or issues building the lines, and these were the first lines I'd ever built. So I say just run 'em!


John

[John Ibele]

In case you run into any issues, Let-Lok compression fittings are made for use on stainless tubing, and Breeze carries them. I used them based on recommendations from others on the forum and can confirm they work well.

[Just 1 More]

3/8 tube to -6an , nothing special about it and very simple
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