Brake Line Flares - Help!

[Morris]

I took have the same brake pipe flaring tool and it's always worked great. Cut the tube square, deburr, set at the correct distance and tighten the 10 mm bolts fully. I don't see how that can go wrong (not a criticism of what you are doing), it just works every time.

 

[barracuda816]

I use plumbers type mini cutters to cut brake pipe - I avoid the Kunifer stuff as well.

That's interesting. I thought kunifer (copper-nickel) was the way to go these days? What do you use instead and how come?

 

[minimutly]

I use plumbers type mini cutters to cut brake pipe - I avoid the Kunifer stuff as well.

Why avoid cunifer? The alternative is copper, which lasts forever but not as robust.
interestingly, the worst (most dangerous) tool I had was a (you guessed it) Sealey. The second tip was so far out of concentric it necked the inside of the flare as it went in. I had one failure, racing in the Border Counties meet, pedal to the floor, on a track that was on a slope and had a "chicane". Otherwise I might not have pulled off....
Another Sealey tool in the bin.

 

[reb78]

Why avoid cunifer? The alternative is copper, which lasts forever but not as robust.
interestingly, the worst (most dangerous) tool I had was a (you guessed it) Sealey. The second tip was so far out of concentric it necked the inside of the flare as it went in. I had one failure, racing in the Border Counties meet, pedal to the floor, on a track that was on a slope and had a "chicane". Otherwise I might not have pulled off....
Another Sealey tool in the bin.

I had the same with a Sealey flare kit i borrowed - it was impossible to get anything I would bolt to my car using it. Truly dreadful to the point of dangerous. I bought one like the OP and have had perfectly perfect flares every time with it - so easy. So hard to see where the OP is going wrong. I do use copper though.

Silly question to the OP - presume the pipe and flare are the correct size for each other? No reason to think they arent but its about the only thing that hasnt been suggested.

 

[premmington]

Why avoid cunifer? The alternative is copper, which lasts forever but not as robust.
interestingly, the worst (most dangerous) tool I had was a (you guessed it) Sealey. The second tip was so far out of concentric it necked the inside of the flare as it went in. I had one failure, racing in the Border Counties meet, pedal to the floor, on a track that was on a slope and had a "chicane". Otherwise I might not have pulled off....
Another Sealey tool in the bin.

I struggle to get kunifer into the shapes I want

 

[Dilkris]

Thankyou everyone for your comments and suggestions - I will post more pics as suggested tomorrow - including that of the pipe cutter.

OK - please see attached photo's, many of which should answer points previously made. I have now literally tried everything, using oil as opposed to grease as lubricant and even annealing the last 5mm of the end of the brake pipe - all to no avail. I have even tried using brake pipe from differing suppliers.
I simply cannot reliably reproduce a good flare - I make 1 good one - then 5 bad - the last photo shows some of the results, out of 25 attempts, 18 of them I would classify as failures and only 7 are good.
I pretty much give in with this and am ready to dig a big hole and bury the whole project - I have been at this for some days and for something so straight forward it is seriously getting me down
A friend of mine uses the same system and I am going to borrow his to see if the fault lies within the die and the punch itself.

 

[voipio]

There's no gripper ridge in the dies, so the tubing has to be exactly the right size, the clamping area and tubing fully degreased in the clamping region, and the die bolts have to be fully tightnened. In fairness, the die has left clamping witness marks, so it looks like it's doing the job, but to give it the best chance, remove all grease from the clamping area.

It also looks on some of the failed flares, that the punch might be trying to pull the flare round, as it's turned, and collapsing it. Have you tried something like Moly-Slip grease on the end of the punch?

 

[Dilkris]

There's no gripper ridge in the dies, so the tubing has to be exactly the right size, and the die bolts have to be fully tightnened. It also looks on some of the failed flares, that the punch might be trying to pull the flare round, as it's turned, and collapsing it. Have you tried something like Moly-Slip grease on the end of the punch?

Not tried Moly-Slip but have used the red grease supplied with the kit - and engine oil - I had not considered that the flare is trying to turn whilst being formed - maybe I should try masking tape (or similar) around the gripped section of the brake pipe in the die to ensure that can't/couldn't happen.
Its worth a try - maybe the OD of the brake pipe is out of spec and inconsistent - or the the machining of the die where the brake pipe is trapped is oversize.
I am honestly prepared to try anything.....

 

[voipio]

It doesn't look like the tubing, or the flare itself is turning. Only that the punch, as it's being screwed in, is imparting a turning moment onto the flare, as it's forming, and creating the stresses that might possibly cause it to collapse. Relieving those stresses with an extreme pressure grease, might be enough to stop it.

 

[Guineafowl]

I’ve done scores of flares with this cheap tool over the years. The only time I had a problem* was early on, when I was overtightening during the OP1 stage. Could this be your problem? It’s only soft metal, so when you feel it go snug, stop.

Maybe try screwing the die down to contact, then going 1/4,1/2,3/4 turn more, etc., and see which is best.



* Other than, the classic - forgetting to put the union on before flaring. I did this twice in one session once, and actually slapped myself in the face with annoyance.

 

[MetalMonkey]

@Dilkris The cutter looks the same as the one I use, but the tube looks a bit "over reamed" and uneven on the outside and not reamed on the inside.

Seems like it is galling up on the end of the pipe, try more lubrication as suggested, and also lubricate the threads of the die as well to make it easier to turn smoothly.
A picture of the end of the die would also be useful to see if it that is malformed.

You should still be able to get a reasonable flare with that tool almost every time - the issue I had with them was the threads didn't last and stripped out.
I also used a cheap clamp type tool like the one above for yonks and it was very hit and miss to get a good flare. The sykes type makes a perfect flare effortlessly every time.

 

[Pigeon_Droppings2]

This is mine

 

[jsf55]

I'm sure i had this problem once before, is it to do with the setting depth ?

 

[steveo3002]

no one local can try a flare on their machine or give you a foot of alternate tube to try?

got the bench mount sykes tool here , theyre rather nice , hard to mess up really

 

[minimutly]

try plus 1mm on the length setting...

 

[Pigeon_Droppings2]

Pic I posted is set up with the stop in the right place...do yours the same and then count the exposed threads. Maybe there's too much tube being exposed because the stop isn't right...just guessing

 

[minimutly]

Not enough is my guess...

 

[Dilkris]

I have tried a washer beneath the setting bolt to increase the length of brake pipe to be flared - same ...
I have not yet tried reducing the length of brake pipe to be flared - will give that a go by say 1mm and then 2mm less.

 

[Dilkris]

no one local can try a flare on their machine or give you a foot of alternate tube to try?

got the bench mount sykes tool here , theyre rather nice , hard to mess up really

I have three rolls of brake pipe here from different suppliers - each pipe behaves the same - **** flares......(sorry)

 

[Dilkris]

I'm sure i had this problem once before, is it to do with the setting depth ?

I'm trying to find out - I just so wish you could remember how you solved the problem