How To Install AN PTFE Fittings To Braided Hose
Posted by Matthew Marks on 2nd Aug 2024
Today, we will cover how to install AN PTFE fittings with Nylon or stainless braided hose.
The methods for this and the normal rubber braided hose are very similar, but the fitting is different and has an extra olive, so we thought it deserved its own guide.
PTFE hoses are the hose of choice for any car running more aggressive fuels than you can get from the filling or petrol station, such as E85 or race fuel, or if you want to run the fuel lines through the car, such as race applications, as PTFE does not allow fuel vapour to escape from the hose. To learn more about the types of hoses and fittings
If you would rather watch a video of us installing the three types of AN fittings and hose, please watch the video below. Also, please subscribe to our YouTube channel, which helps us massively!
Now, let's move on to the tools you need to assemble your PTFE hoses.
Tools Needed To Install AN PTFE Fittings:
You will need a few tools to install the PTFE fittings more easily. I've added an optional section, but I always recommend using the tools here, as they help you avoid damaging the anodised fitting when trying to install it.
AN Parts needed:
Tools Needed:
- A vice installed on a bench
- A roll of masking tape
- A tin of WD40 or grease
- A microfibre or clean cloth
- A tape measure
- A disc cutter with a 1mm cutting disc
- Goggles or eye protection
- A spanner in the correct size for the AN PTFE fittings
Optional Tools:
1. Cutting The Braided PTFE Hose
You will need to start building the AN line by cutting the PTFE hose. First, measure the length of the hose you need and mark both ends with masking tape. Ensure the masking tape has the cut line through the centre.
We use masking tape rather than anything else because it will hold the braid together when installing the PTFE fittings, does not fray, and does not potentially damage the fittings' thread.
Now that you have masked both ends put the hole in the vice using either the aluminium vice jaws or the clean cloth from the tools section.
Overlap the hose around 10mm-20mm over the vice, holding it in place when cutting. Install the 1mm cutting disc into the disc cutter, put the goggles on, and cut through the centre of the masking tape.
Once you have cut both ends, fully blow out the line to ensure there are no metal shards inside the PTFE hose, as this can be potentially fatal for your engine.
Now you have cut the hose correctly, we can move on to installing the PTFE fittings.
2. Installation Of The AN PTFE Fitting To The Hose
Now, we move on to putting together the AN braided line. Follow our steps below to install your PTFE fitting easily and quickly.
First, you want to unscrew the fitting and remove the aluminium olive from the centre. Keep the olive aside, as you will need it in a minute.
Push the end of the AN fitting over the braided hose with the tapered edge pointing towards the end of the line.
Install the Olive at the end of the line between the braid and the PTFE, with the tapered edge pointing inwards. You will know when it is installed correctly as the PTFE inner of the hose will sit against the lip inside the olive, as shown in the photo below.
Put some grease or WD40 on the male end of the PTFE fitting and start pushing it inside the PTFE line. You will know when it's done as the end of the olive should touch against the threads.
Now, pull the female part of the AN fitting down the line and thread it onto the base of the fitting by hand. Go as far as you can, then install the fitting into the Vice with a cloth or jaws.
Make sure the fitting is seated correctly in the vice with a few millimetres of overlap to ensure you don't damage the spanner or fitting, and tighten the female end as far as you can go.
The best method that we have found is to try and turn with one motion without stopping; this seems to make it a little easier to screw the fitting down.
The fitting will more than likely not fully bottom out against the female part of the fitting as the olive is the part that will seal the line. Once the fitting has been screwed as far down as you can, you are all done!
Please pressure test the line before installation to ensure you have no leaks and you can install it on the car!
Frequently Asked Questions:
Q. Can I use normal AN fittings instead of PTFE fittings with PTFE hose?
A. No, you must use PTFE fittings with PTFE hose as the specific aluminium olive seals the line.
Q. Can I use a jubilee clip on the end of the PTFE hose instead of a fitting?
A. No, you will have to use the specific PTFE fittings, as the PTFE inner will not clamp around a barb or push fitting correctly and will leak.
Q. Can I use PTFE hoses for normal pump fuel?
A. Yes, you can; the PTFE line suits any standard pump or race fuel. Most people don't use it for this, though, as it is more expensive than a rubber inner hose. However, it allows for a wider range of fuels in the future.
Q. Can I run a PTFE hose inside the car?
A. You can run a PTFE hose inside the car, ensuring it doesn't rub on any metal bodywork, is fully secured, etc. PTFE is great for race cars as it doesn't allow fuel vapour to seep out like a normal rubber hose, and sometimes, it is a requirement in racing applications.
Q. Can I make PTFE lines without the aluminium olive?
A. No, you cannot make a PTFE line without this. The olive is there to seal the line, and without it would leak.
Q. Is the PTFE aluminium olive reusable?
A. No, you cannot reuse the olive, as it has been designed from aluminium to crush to be able to seal. Although you can buy replacement olives for your specific line size, they are cheap!
Products Used In This Guide:
If you want to buy any PTFE fittings to build your own line, the link is below this guide on mobile, or on the floating sidebar to the right on desktop.
We have used these specific fittings in this guide and our own race cars for years, and they have never caused any issues.
Conclusion
So there you have it—the full guide to installing AN PTFE fittings on nylon or stainless braided hose.
If this guide has helped you, please let us know in the comments below!
And if you want to order anything from this article, we have a specific discount only for our blog readers. Use this code at the checkout:
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For more related articles, have a look at some of these below:
- How to install AN fittings to rubber braided hose
- What does an oil catch can do?
- The ultimate guide to AN fittings
- What is a swirl pot?
If you are still unsure about anything in this guide or need help, please contact us. We will be happy to help!