Brake line flaring

[mathew]

Been away from the exocet for 4 weeks due to working away but now im back in the shed grazing my knuckles and swearing a lot. Todays mission was to bleed the brakes but came across a slight problem.....

Went into the new brake line installation like a bull in a china shop and should really have done some research first. Long story short most of my connections leaked!

After doing a lot of reading i have come to the (easy) conclusion that my flares on the copper pipe were sh**. After doing a bit more reading i noticed there are different type of flares which leads me onto my question......will a single flare suffice or do they need to be double flares? Im hoping a single will be good enough as the flaring kit ive got is only capable of a single

[samuelt]

Good question I am about to start my brakes and have no experiance in this filed. Very keen to find out as well.

[sspogman]

Single flare should be fine, that's all that I had.

With hindsight, I would probably spend a bit more on the flaring kit and make life easier - I had a cheap one off of eBay that was hard work...

[The Joker]

Hi Mathew,

The flares you make on the tube needs to be the opposite of the one in the receiver port that you are connecting to. This is the only safe way to make a connection even if you do get a 'seal' with the wrong flare. Fitting a single (or convex) flared tube into a receiver port designed for a double flare can damage the seating cone in the receiver port and lead to problems even when you then fit the correct flare! Check for damage first.

There are different angles of double flare but most likely all the ones you need will be 90 degrees. There are also different fittings to suit either convex (MCF) or double flares (MDF) identified by a cone in the nose of the fitting for MDF or a flat nose for MCF. From what I have seen most aftermarket fittings appear to have a small radius on the nose probably with the intention of using them with both flare types....hope this helps

[mathew]

Thanks for the replies guys.

After even some more reading regarding brake lines i've decided to go down the double flare route for peace of mind. Ordered a double flare die as my el' cheapo kit didn't have one.

Whats peoples opinions on using PTFE/teflon tape on the threads of the unions? General consensus online seems its a no no but none seem to actually say why. I understand the thread doesn't form the seal and its actually the flare but surely there's no harm in taping the thread as well so if there was a slight leak on the flare the taped thread acts as a back up?

As you can most probably tell im not holding out much hope of my new flares being leak free

[dinosaurjuice]

i ran full length stainless braided hoses from master cylinder to caliper. cost about £100 for loads of fittings and 12 m of hose. theres no noticeable difference in pedal feel and the chance of leaks is minimal.

i just dont like the idea of copper pipes, and didnt have access to the snazzy steel ones joker had made!

[gwnwar]

Double flaring is the way to go with brake lines. as is stainless tube.. you can buy different sizes of tubes made up with fittings preflaired and put them together with unions..use a tube bender tool for a pro looking job.. If you are going to do your own, work with some scrap pieces first till you master it.. info on how to do it should come with kit and how much to leave sticking out of the clamp to start with.. Stainless is harder to work with but looks better and will not cramp or leak if hit by something on the road..

[The Joker]

OK, just to be clear, you have to make a flare that is compatible with the seating face in the receiver port (master cylinder, caliper, tee piece, etc) it isn't a case of deciding which one to fit; you will have already had the decision made for you when you selected your calipers/master cylinders, etc. You may find that you have a mixture of both on your set-up and you will have to make the opposite (and matching) flare on the tube.

Do not use PTFE tape on the threads! The seal is created by the flare only and the fitting only applies the load to create the seal at the flare. Applying PTFE will give false torque feedback when assembling the joint (potentially causing leaks) and could cause the joint to loosen over time (potentially causing leaks).

If I had to choose between aftermarket brake tubing I'd use Kunifer (Cu/Ni) first based on cost then PTFE lined Stainless Braided hose with fittings.

[mathew]

The Joker, my plan of attack was/is to replicate the flares that are on the ends of the old brake lines.

[ecowindman]

Hi guys

In don't here of anybody useing the existing brake & fuel lined mine where in good condition so I removed them one by one and where they where bent to the mx5 chassis shape I heated them slightly with a hot air gun and bent them straight then fitted the all on to the Exocet chassis before the engine .worked well with no issued . But I was lucky they where in good shape no rust

Geoff

[John B]

I plan on doing the same as Geoff.
Is there a reason why more people don't do this?

[ecowindman]

I think that a lot of the doner have underbody rust and pipes could be suspect ,I was lucky and they where good .i even straightened the brackets to clip them in to the chissis

Griff

[red5]

Ive reused mine and rebent to shape , no probs - i think build budget is another driver