Thread: Plumbing the chassis

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Originally Posted by ceh383

I would have to disagree. It is almost impossible to do it most flaring tools, but it can be done. HERE is a tool made for 37deg double flares to AN standards. Not the kind of tool you find in most garages.....

This $585 thin wall tubing tool you show a link is for copper and aluminum only according to the information. You cannot safely use either metal for tubing brake lines on an automobile. Try to double flare with SS and you will split it around the circumference of the bend fold. Why would you even want to consider double flares in AN fittings that are designed for and only require a single flare?

This is a sore subject with me and it is not over yet. First, the Speedway 37 degree flare is junk, mine broke on about the fourth flare of stainless tubing. Second, IC2 is correct that stainless work-hardens and what ever you do at first is it, there can be no corrections. Third, of course, put the fittings on before you flare both ends! I am no expert here, just a frustrated first time user, although I did work on an assembly line flaring many copper tubing connections in a refrigeration manufacturing plant. After several failures and split ends even on single flares I measured all the lines needed and took the tubing and fittings to John York who has a nearby shop building turnkey Cobras. John did a great job using a very old surround clamp in a vise and tapped down on the ends with a dimpling tool for a double flare. With a little patience and persistance I got almost all the lines sealed but I just could not stop a leak to the left front wheel at the tee. I replaced the tee and the line but still the second line leaks at the tee. I tried adding a short wrap of teflon tape on the joint but it still leaks "a little". This is an unacceptable situation but I have postponed replacing it a second time and will have to fix it before driving! In the back of my mind I think I will have to take the car to John York's shop and see if he can replace it again and get a seal. Soooo, the question is do you really want/need stainless? If you get it right, it is forever, great! I have looked at the end which leaked and the flare did not crack, it just seems to be slightly assymetric in the AN fitting so I suppose/hope that if I keep replacing that line I will eventually get it right. On the other hand you could use precut steel lines with the ends already flared from an auto supply shop and paint the lines and be good for ten years. As I see it a first timer should use ready made steel lines OR pay a pro to do stainless lines. I thought my experience with flaring copper lines would make working with stainless an easy job, but stainless is tough to learn on. Now I am stuck with this leaking line and I guess the main thing to do is to make sure the double flare is symmetric in the AN fitting. For the record, John York assumed that 37 degree stainless should be doubled-flared.

Don Shillady
Retired Scientist/teen rodder

Originally Posted by Don Shillady

This is a sore subject with me and it is not over yet. First, the Speedway 37 degree flare is junk, mine broke on about the fourth flare of stainless tubing. ........

For the record, John York assumed that 37 degree stainless should be doubled-flared.

Don Shillady
Retired Scientist/teen rodder

Don,
I agree with you about the Speedway 37* flare tool - I went that way first then spent the big bucks.

SS is really not tough to work with as long as you understand what has to be done. It is a bit difficult to bend as tightly as CS as it is harder material and has some spring back. I would run, not walk away from your buddy when it comes to working with SS brake lines as he doesn't, to me, have the tools. If it's cut square, and the tool is in good shape, there should never be an asymmetric flare. The tool I show above will run the flare down to the proper size then "breakaway" so you don't over do it.

Using the tools pictured above, I made all of my connections (lots of them) and had one minor seep at the proportioning valve and one at the MC which I corrected with a bit more tightening. The system was filled about a year ago - and ten minutes ago - no new leaks.

Unfortunately auto supply shop lines come in pre cut lengths and have never been "just the right length" for any car I have ever done.

Originally Posted by IC2

This $585 thin wall tubing tool you show a link is for copper and aluminum only according to the information. You cannot safely use either metal for tubing brake lines on an automobile. Try to double flare with SS and you will split it around the circumference of the bend fold. Why would you even want to consider double flares in AN fittings that are designed for and only require a single flare?

If you read my first post you would see I never suggested a double flare for an AN fitting. I stated "It can be double flared but it is not necessary or advisable"
The tool I linked to was only to show it is possible and there is a spec for a double flared AN nothing more.

Originally Posted by DennyW

I'm sorry Chuck, but that's not what I read... They will also split.

((Originally Posted by IC2
You cannot use a double flare with AN fittings - they will not fit the sleeves.))

I would have to disagree.

It is almost impossible to do it most flaring tools, but it can be done. HERE is a tool made for 37deg double flares to AN standards. Not the kind of tool you find in most garages.....

Not 500+ dollars for the home mechanic either. That's why you buy lines already done, if you go stainless. Same as exhaust pipes on the bends.

Why would you want to double flare SS brake lines for fittings that weren't made for it. 3/16" SS tubing will crack when you fold it over. If I was to use standard Bundy carbon steel brake tubing I would have double flared the ends using my double flare tool (not shown above) and the proper 45* fittings

There is no way that I could have bought pre made brake or fuel lines for my car. That's why I bought the good Rigid SINGLE, 37* tool kit.

Exhaust tubing - again, no way to buy a pre made exhaust system for my car. It's a welded system with a few slip joints, using 'U' and 'J' bends and a length of aluminized steel exhaust tubing

At this point I have enough leftover tubing to try a single flare or two; it does look like there is more material to overlap the nose of the male part of the AN connector. I think when you use a double flare the ridge is stronger but more narrow with less chance to fully cover the nose of the male connector. On the other hand it looks like I will just have to try and retry until I get it right.

Don Shillady
Retired Scientist/teen rodder

I hadn't thought about using pre-made lines, but I would likely need to cut one or two and then flare it and at that point I may as well just do them all maybe.

so how bad is the steel line then? I had only thought of it rusting out due to road conditions and not as much just sitting. They rust on the inside and out? Come to think of it, one of the brake lines on my 10 year old Blazer rusted out, but it had a few owners up north and is all rust on the bottom. How much do I have to worry about using steel line? not only does stainless cost twice as much, but it sounds like it's harder to work with and I have yet to save money on any part of this car is this a possible place to cut costs without paying more in the end?

the braided lines W/O DOT on them...are they legal or should I avoid them altogether?

Thanks