Plumbing - Brakes and Fuel

**elspanishgeek** · 12-01-2022, 03:48 PM

Hey y'all,

After lot of research throughout the forum (particularly from Paul's build threads) I'm getting ready to run all my plumbing. However, I wanted to do a sanity check with the configuration I created before bending, flaring, and hooking up.

Brake Plumbing
brake_diagram.JPG

Components:

3/16'' tube of 316L stainless steel
Earl's -3AN stainless steel adapters and fittings (Tube nuts, tube sleeves, T-unions, single unions)
Wilwood's flexlines and 45-degree caliper fittings included with the upgraded Wilwood brakes

Fuel Plumbing
fuel_diagram.JPG

Components:

3/8'' tube of 316L stainless steel
Earl's -6AN stainless steel adapters and fittings (Tube nuts, tube sleeves, single unions, AN to 3/8'' NPT)
Breeze's 190 LPH in-tank fuel pump with 3/8'' outlet and 3/8'' supply and 1/4'' return 6AN adapter kit
Aeroquip's -6AN Teflon racing hose and reusable PTFE fittings
Holley's 10 micron fuel filter and adjustable 3/8'' bypass regulator

Sanity Checklist
There are three main things I would be incredibly appreciative to get some more info on:

- Has anybody else done all their plumbing using AN fittings and 37-degree single flares? I have the right tools for flaring, which shouldn't be a problem for fuel lines but now I got a bit worried after watching some YouTube videos with regard to the high pressure of the brake lines.

- Has anybody used Earl's stainless steel fittings? Again, not really a concern for the fuel system, but I couldn't find the pressure rating on the website. I did call Holley and after a 12-minute hold, the technician told me their fittings are rated for 3,000 PSI. However, he didn't inspire much confidence in his response.

- I didn't think stainless steel galling was a concern unless you had very high heat but I'm finding several posts saying they never threaded any two stainless steel pieces without anti-seize. Yet, I've also read that you do not want to add anything to AN fittings because it can compromise the seal. Has anybody had any bad experiences running all their plumbing with stainless steel? and did you use anti-seize?

Thank you!

**Mike.Bray** · 12-01-2022, 07:01 PM

I can possibly help here as I've done stainless steel brake and fuel lines with 37 degree AN flares for decades. I can tell you number one you want good quality seamless stainless steel tubing as the 37 degree flares are single flares. I used Earl's 3/16" SS tube for the brake lines and it worked fine. I couldn't get 3/8" stainless from Earl's at the time for the fuel lines so I tried the Summit brand which failed miserably. It would crack and split when flaring. And I've got a very good Eastman burnishing flaring tool. I ended up using compression adapters to AN like these for the fuel line fittings. EFI fuel lines are relatively low pressure, 40-60 PSI, so even aluminum AN fittings are overkill.

Why are you wanting 316L stainless? 304 will work fine is is easier to source and cheaper. I don't see any advantage in 316L for this application.

For the pressure side on my brakes I used Earl's steel zinc plated fittings, tube nuts, and sleeves. I've used aluminum in the past on street rods but the zinc plated steel is a little extra insurance. You can use stainless fittings, you'll just pay 2-3 times for each. And yes, anytime with stainless to stainless thread you want a little anti-seize. But nothing on the flare itself, only on the threads of the AN fitting and tube nut. A small amount. Don't make a mess.

For flex hose on the fuel lines you definitely want Teflon lined for today's fuels. Check out Hot Rod Fuel Hose, good quality stuff at a very fair price. I used it on my car and was very happy with it. Nice people to deal with also.

Hope this help.

**elspanishgeek** · 12-02-2022, 09:47 AM

Mike this helped tremendously, thank you! To answer your questions, going stainless seemed like a good idea for all the hardlines (even if harder to bend and flare) and when I went looking for a supplier that I could drive to and pick up the tubes, the ones they could provide me were 316L. Then I went with all SS fittings to avoid any potential galvanic corrosion.

Have you had any issues getting cars registered with brake lines using 37-degree flares with AN fittings?

**Mike.Bray** · 12-02-2022, 10:31 AM

The 316L will work fine, it's just a bit more than you need for brake & fuel lines metallurgically. You want 3/16" OD x 0.028" WT for the brake lines and 3/8" OD x 0.028" WT for the fuel lines. Make sure it's annealed and seamless. If you run into trouble you can always source Earl's tubing.

For bending I have a set of the old Rigid lever benders which I don't think they make anymore. Fragola make very similar benders like this one. These work well with stainless tubing and are very precise, you can put a bend exactly where you want it. Here's some fuel lines I did a few years ago.

AN fittings are aerospace grade and superior to standard SAE components. You're the first to ever even mention issues with inspection/registration because of AN fittings to me! You should be fine.

**elspanishgeek** · 12-03-2022, 05:32 PM

Yeah got a 3/16'' and a 3/8'' Rigid tube benders and I'm doing some practicing with some steel lines I got from Autozone for the cheap. Hope my end product will look as nice as yours!

**elspanishgeek** · 04-07-2023, 10:23 AM

I finally was able to get started with the plumbing for the 3/8'' stainless steel fuel lines (from Brakequip) but after doing several practice bends I want to check something with y'all. I got a bender that was recommended in several threads (https://www.summitracing.com/parts/ear-028erl), though, it says Imperial on the back. I'm not sure if I'm doing something wrong, if the tube is wonky, if the tool is not the appropriate one, or if everything is OK and I'm just being too finicky. Here are the two issues:

Slight flattening and clamping
vlcsnap-2023-04-07-09h49m38s812.jpg

Kink left from the mandrel
vlcsnap-2023-04-07-09h50m17s834.jpg

Here's a very short video for better viewing: https://i.imgur.com/ObVVdVQ.mp4

Also, here the bender
bender1.jpg bender2.jpg

Are any of these a concern or can I proceed to complete my fuel lines?

**Mike.Bray** · 04-07-2023, 11:09 AM

That doesn't look like a bad bender, it should be making better bends. Are you sure you have the correct wall thickness? Is the tubing annealed?

If you get totally stuck you can send me a short piece of your tubing and I'll try it with my bender. I know what bends from it should look like.

**elspanishgeek** · 04-07-2023, 11:21 AM

Hey Mike! Yeah, annealed and with 0.028'' thickness (From BrakeQuip: https://brakequip.com/products/tubin...-steel-tubing/), unless the distributor gave me something else and tried to pass it as BrakeQuip. I too am puzzled because the tool comes highly recommended and well-reviewed. I'm trying to see if I can rent a SwageLok or Rigid bender to test, but if not, I may have to take you up on your offer.