Technical Why does almost every fitting on my brake system leak?!

Why Unions? On a car that small wouldn't you buy sticks that were long enough? don't kill me, just curious

 

When I did my 51 Convertible, I too used silicon fluid. I had leaks everywhere. I just tightened and tightened until they stopped. silicon fluid is known to do this. Don't take it all apart. Just retighten.

 

The black nuts have me wondering if you're using metric fittings and if the nuts match the unions and Ts.

 

If they do then they are pretty damn close because they thread in no problem. None of my wheel cylinders are leaking

 

I may be doing it wrong. When I cut the lines with a tubing cutter it leaves a rough edge. I relieve the crushed inner part of the tube to get the burrs out. I file the ends flush and flat. I also lubricate the tip of the flaring tool well. Then I tighten and retighten the flare several times while rotating it to a new position each time. I then clean everything before assembling. I have always had good results. I use Imperial flaring brand.

 

Are you sure that is a 45º flaring tool, and not a 37º flaring tool?

 

I was asked that by a friend of mine. I should be using 45* correct?

 

Correct 45*
37* for Stainless, you usually don't double flare Stainless.

 

Yes.

 

A little anti-seize on the threads or oil helps keep thread galling down.


Sent from my iPad using The H.A.M.B. mobile app

 

i think you need a new cutter wheel. there should be no burrs and it should cut the tube flat. use a file to bevel the out sides of the end of the tube, that will help the tool fold the tube in on it self.

 

I ran mine the exact same way. I expected some leaks, but I did not have a single problem! I have a rigid cutter and I debur it with the tool that swings out on the cutter. I then file the edge quick with a bastard file.
I have an old forge flaring tool. The key is not to go crazy. You just want the rough shape. When you tighten the fitting on the car, it crushes the rest of the way. I only tighten once, remove the die, and then double flare only once.

 

As stated earlier when making the double flare dont crank the snot out of the flare tool on the 2nd step with the cone part of the tool. Get the double flare formed but let the fitting make the final seat when installing the line, works for me. With all of these fittings probably made overseas who knows what the tolerances are on the dimensions if the cone in the fitting. I make my own lines for all of my builds from 25' coils of line, no unions needed either.

 

Only if you are a hackmaster general.

 

I like to look closely at the face of the flare when its done. I'll tough it up slightly with a file or sandpaper if it is a little rough. Make sure the anvils are not scored up. I borrowed a buddy's hydraulic tool and touched up all the anvils for him.

Make sure the degree of the flare angle matches the components you are using.

 

Good subject guys! Bruce.

 

I want to try to anneal the copper washers on my junction up front as well. Heard that could help

 

I haven't seen a mention of lubrication [may have missed it] but I was taught to lube the end of the tube and the flaring tool. It makes mine better I know.

 

I agree, also if you buy the NiCop reel it's easy to bend without a tool. I did my whole corvair with it. Great stuff.


Sent from my iPhone using Tapatalk

 

This really does work!

 

Partssaloon i have a few things I'm going to try today but will plan on ordering that in time for next weekend.

 

I have a total of 3 unions. Two for the rear where the 60" brake lines ended, and one up front at my crossmember which I am currently looking into omitting

 

I'm telling you, a spool of the NiCop or even a spool of steel line, this way you make one straight shot with no extensions or sections. The only unions I would use are ones to split the main line into a left and right. Nothing wrong with doing it the way you have it, but it's one more thing to leak.


Sent from my iPhone using Tapatalk

 

There is absolutely nothing wrong with using unions, properly flared lines should not leak period!! Omitting the unions isn't solving your problem. As said before, try tightening and loosening and tightening a few times and I bet the leaks go away. When forming flares lubricating the cone that flares the line is a wonderful idea, just don't use anything other than brake fluid!! Brake systems do not tolerate any contamination!


Sent from my iPhone using The H.A.M.B. mobile app

 

I use antiseize on the tubing nut, inside and out and tighten them really tight. I prefer steel unions because the threads can strip in the brass.

 

I've used the same line, and same flaring kit that every guy on here probably has. The pic of your crimp looks OK, It centered and doesn't appear to be crushed.
I have found bad brass unions, some manufacturers seem lighter than others. Look at some from a few different parts stores and you'll see what I mean.
Then just make sure they are good and tight!

 

I have had problems with new line and work hardening the ends when I cut it with a pinch cutter ( the one with the wheel ) so I cut it now with a fine tooth hacksaw and blow it out with solvent , also after forming if you can find them get a female union in steel ( they make them but are hard to find , older cars have them ) and then oil the nut and backside of the flare so you lower the friction and then put it in and tighten and loosen 5-10 times and progressively crush the flare down when you see the seating ring in it , it shouldn't leak no more , I have stripped out several brass unions trying to get a new flare to seat they are just too soft to torque down on . as for unions Vs one piece , I still like unions as it allows me to work the section better and tighter and its easier to manuever in to place .

 

After cutting the tube with a tubing cutter with a sharp roller blade, I dress the end with a flat fine file, then take a hand held countersink and clean up the burr on the i.d. of the tube. After the final flare, I lightly use the countersink to perfectly finish the tube seat. I also squirt a light drop of Gibbs on the tube to lube the flaring insert.

 

Partsaloon beat me to the draw on the Koul Tool, I read about it somewhere else, maybe SR, not sure.
I have one of their kits to insert fittings in AN braided hose and it works great. If this works as well it'll be worth having. I plan to buy one soon.
The Loctite stuff mentioned in post #24 is FAA approved, at least for light aircraft, don't know about airliners. Got some from a buddy who had bought it for light plane he owns.
My roadster was already a rolling chassis when I bought it with SS lines and 37* AN fittings and it leaked like a sieve! That Loctite stuff is more of an anti seize than anything else and does allow you to get fittings tighter. Some of mine still seep a little though, so I'm going to get one of those Koul Tool flare hones and try it

 

So quick update. Progress was made today but I'm still chasing down leaks here and there.
But check this out, the banjo bolt I bought was total junk. Didn't have the right bevel on the end, and the hole for the fluid didn't line up at all.




So I refurbished an old one I had lying around:


And after some polish and scotch brite