Poor poor rusty Miata

I finally got under the car to look at the leaky hard brake line. Popping off the plastic clip that holds the four lines together ruptured the rusty rusty gas line. Even jacking the car up was enough to deform the frame rail.

I suppose I could replace the sections of rusty hard gas tubing with rubber with little difficulty. The rubber line attached to the hard line looks to be in acceptable condition.

But what about the brake lines? I am just not sure how to do this. They are all rusty right up to the point where they turn upward toward the brake splitter block. I don't know how to proceed.

Locate suitable replacement car on ATL CL, fly into ATL, drive home rust free Miata.

Let's say for the sake of this post that my budget does not exceed $50.

Make up some new hard lines. It's a PITA, but not "hard" really. Just tedious.

Better yet, yank the drive train and build a Locost. Some dude wrote a book about building one from a Miata.

I think it's the process of making the new hard lines that is throwing me off. I don't know how to do this. I don't know the magic of flaring and attaching.

Lugnut wrote: I think it's the process of making the new hard lines that is throwing me off. I don't know how to do this. I don't know the magic of flaring and attaching.

Steel may be difficult to work with your first time however, I've been reading about this stuff for a while and have just recently noticed it showing up on the shelves of local parts chain stores.

It is called cunifer, as it is copper, (ni)clke and iron (fe) and should be significantly easier to bend/ flare etc.

quick write up ARTICLE Happens to be a scan from Skinned knuckles, my other favorite magazine.

Don't be discouraged this is not a difficult task, you can do it If you run into trouble, talk to the friendliest guy at the parts store who sold you the new line, should be able to help.

Brakequip's flaring tool is less than a nice dinner away from what I paid for the entire car.

I suppose I will look at the auto parts store tools and see what I get.

I had to replace rusty lines on the Crown vic when I still had it. It turned out really crappy, but it worked...

Most parts stores have pre flared line in different lengths too if you dont want to do the flaring. You'd still have to bend it but that's easy compared to flaring.

Cheap flare tools will work (barely) but make for a miserable job. Good flare tools are expensive for a reason, they are worth it.

JThw8 wrote: Cheap flare tools will work (barely) but make for a miserable job.

I had one flare to make. Yup, miserable is a good word for it. But I eventually got it done. If it's one line, you can probably make it work. The pre-flared lines from the auto parts store may do the trick if you can find one the right length. Sure is a lot easier. Worth a shot.

fast_eddie_72 wrote:

JThw8 wrote: Cheap flare tools will work (barely) but make for a miserable job.

I had one flare to make. Yup, miserable is a good word for it. But I eventually got it done. If it's one line, you can probably make it work. The pre-flared lines from the auto parts store may do the trick if you can find one the right length. Sure is a lot easier. Worth a shot.

If you do them with any frequency (or dont mind investing in something for future use) this one from Eastwood frequently goes on sale for about $150, less than other good tools but still not cheap. But use it once and you'll love it

http://www.eastwood.com/professional-brake-tubing-flaring-tool.html

I bought one while building the Wartburg and it was a life saver.

In the past, especially in emergency situations I've had good luck with buying pre flared line and if its too long a couple of gentle wraps around a spray can will shorten it up if you cant get an exact length.

JThw8 wrote: If you do them with any frequency (or dont mind investing in something for future use) this one from Eastwood frequently goes on sale for about $150, less than other good tools but still not cheap. But use it once and you'll love it

I just watched the demo video. That's pretty impressive.

Pardon the potentially stupid question. Is the proper way to redo the entire line, or to cut the damaged sections out and splice in replacement sections?

Lugnut wrote: Pardon the potentially stupid question. Is the proper way to redo the entire line, or to cut the damaged sections out and splice in replacement sections?

The entire line is always the correct route. I have, admittedly, in an emergency put in a splice. But that was a BABE rally style repair only to be replaced at a later date.

There are "repair" splices sold which use a compression type fitting that are not safe. If you want to splice correctly you need to flare the cut side and use a union fitting between the old line and the new line, but trying to flare a line that is still on the car is very difficult which is why most folks resort to the compression fitting.

Flaring both sides with a union can be a permanent repair, but any type of fitting that lets you splice in without flaring should be considered a temporary emergency fix at best.

Ok, that's a great answer. Thank you!

Now, I hope the last question: What kind of flare does the Miata brake line use?

Lugnut wrote: Ok, that's a great answer. Thank you! Now, I hope the last question: What kind of flare does the Miata brake line use?

Just about everything except euro cars uses the double inverted flare (euros use bubble flare)

If you buy pre bent line they will have it marked as American, Euro or Japanese, just get the japanese and you'll be fine

You know, Mazda sells pre-formed Miata hard brake lines for ridiculously cheap through the motorsports program. I did all the lines in my car (hard lines, and braided stainless flex lines) for well under $200. It was a pretty easy job IIRC. If you are just doing the 2 lines that meet at the block in the rear, it will be under $50. All the hard lines in the car are under $100.

Also, those rails under a Miata are NOT frame rails. Jacking at the wrong place on those could have deformed a brand new chassis, not to say that they weren't rusted to bits on your car though :).

I am still awaiting my response from the motorsports program.

If you tell them you are building a car and need parts now to get it ready for racing, they will sometimes waive the race results requirement, or at least that was the case 4 years ago when I bought my Miata. In any case, calling is generally a better way to get them to acknowledge you than blindly sending emails.

I already sent in my race results over the winter, I just haven't heard anything.

I don't think they did anything with mine until I called either. If you need something now, it couldn't hurt to ask.

I had a lot of rust on my astro... ended up having to run lines on it... that was a 1st... and because it was an ABS van the master junction box sat under the drivers seat (under the body)... the passenger front line died and I ended up running 2 pieces of the pre-flared stuff... outside of removing the engine I don't know how it could be done with a 1 peice line...

I barrowed a friends bending tools... he had the simple cheap one and a higher end one... I honestly prefered the smaller cheap crappy one...

then once that one was fixed the rear line died... because it ran between the gas tank and the frame rail (prob inside the frame rail C section) i ended up routing it around the other side of the fuel tank... hung it with rubber covered bolt on hose run thingies...

also the fuel line from the fuel tank to the fuel filter died... all of this was due to rust... so I picked up a fuel line repair kit... unfortunately that would mean pulling the fuel tank... so I ended up running the replacement line from the filter to close to the fuel tank line and used a few inches of EFI hose with double hose clamps on each side.

move to a month or 2 ago... a friend calls me with the brakes out... head out to find the rear line is dead right somewhere between the wheel well and the pumpkin where the soft line runs... because of the way the line was run I ended up cutting the stock line up in the wheel well (there was enough of a run that I was able to bend it out to be able to cut and flare it)... the rest I used a pre-flared line...

I had never done a double flare before... I borrowed a harbor freight kit from a friend... had to use a C clamp on the holder portion so the line wouldn't slip out of the clamp... but it worked ok... I just practiced about 4 or so times with the spare line i'd cut out...

yes you SHOULD use a single run if possible... but when you use pre-flared lines thats not possible with a longer run... also figuring out how to get it all in is fun :-/...

if I had to do it again I'd prob just buy a decent flair kit and a roll of line and build it from scratch... a little time practicing with the flair kit goes a long way... cut a little long and you can take out the length somewhere else... or if you fudge it up you can cut it again and still have enough room to fit.

best of luck mark

The brake line on my 1990 Miata got so rusty I had to replace it. It runs from the junction block in the back all the way up to the master cylinder, but can be snaked out through the hood if you have the car up on jack stands. I didn't mess with bending my own line. The Mazda part wasn't too expensive, is coated, and has protection where it could rub against stuff. I just don't like taking chances with brakes.