Straightening copper pipe

[JohnHWSteedman@aol.com]

Fitting new copper brake lines to the TC, I've managed to flatten the tube whilst I was doing the fiddly bit through the chassis by the left hand three way brass junction. The kink is only 3 "" from the end of the pipe and I've thought of heating it up and trying to force a knitting needle through to open it up. Any more scientific tips would be appreciated, plus an explanation of how I should have tried to bend it in the first place. My plumbing manuals for heating systems describe a spring insert, which is pulled out when the bend is complete, but I doubt whether that's the right method for small bore tubing. My thanks to the list in advance, John Steedman, TC0301

[Dave Norris]

John, Having flattened the brake pipe I don't think it would be at all advisable to try to return it to its previous shape. Safer I would have thought to cut off the offending piece a few inches back and connect a new length. Your plumbing manuals must pre-date microbore (!) To bend small bore pipe (including microbore) you need an [u]external[/u] bending spring. Cheers, Dave Aberdeen TC9964

----- Original Message ----- [b]From:[/b] JohnHWSteedman@aol.com [b]To:[/b] mg-tabc@yahoogroups.com [b]Sent:[/b] Friday, August 03, 2001 6:31 PM [b]Subject:[/b] [mg-tabc] Straightening copper pipe Fitting new copper brake lines to the TC, I've managed to flatten the tube whilst I was doing the fiddly bit through the chassis by the left hand three way brass junction. The kink is only 3 "" from the end of the pipe and I've thought of heating it up and trying to force a knitting needle through to open it up. Any more scientific tips would be appreciated, plus an explanation of how I should have tried to bend it in the first place. My plumbing manuals for heating systems describe a spring insert, which is pulled out when the bend is complete, but I doubt whether that's the right method for small bore tubing. My thanks to the list in advance, John Steedman, TC0301 Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

[C Sherriff]

Message text written by INTERNET:JohnHWSteedman@aol.com

>Fitting new copper brake lines to the TC, I've managed to flatten the tube

whilst I was doing the fiddly bit through the chassis by the left hand three way brass junction. The kink is only 3 "" from the end of the pipe and I've thought of heating it up and trying to force a knitting needle through to open it up. Any more scientific tips would be appreciated, plus an explanation of how I should have tried to bend it in the first place. My plumbing manuals for heating systems describe a spring insert, which is pulled out when the bend is complete, but I doubt whether that's the right method for small bore tubing. My thanks to the list in advance,

[Roger Furneaux]

Re: [mg-tabc] Straightening copper pipe John - the correct way is to use, wait for it, a "pipe bending tool"! This has a grooved cylinder with grooves for the common sizes of pipe, and a swivelling arm to ease the pipe around. you can get them from firms like Frosts, or borrow mine if you happen to be passing... I would not try to unkink it, tubing is cheap enough, you already have the unions, now all you need is somebody to lend you a flaring tool (try Eric) cheers Roger

[quote] Fitting new copper brake lines to the TC, I've managed to flatten the tube whilst I was doing the fiddly bit through the chassis by the left hand three way brass junction. The kink is only 3 "" from the end of the pipe and I've thought of heating it up and trying to force a knitting needle through to open it up. Any more scientific tips would be appreciated, plus an explanation of how I should have tried to bend it in the first place. My plumbing manuals for heating systems describe a spring insert, which is pulled out when the bend is complete, but I doubt whether that's the right method for small bore tubing. My thanks to the list in advance, John Steedman, TC0301 Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service [u]http://docs.yahoo.com/info/terms/[/u]> .

[/quote]

[DAI]

John, As per the others, it is not recommended to straighten a pipe once it has started to flatten. I bought a set from a well known T-type supplier, but found the long pipe from the 3-way to the rear axle, to be about 2 inches too short. I couldn't get the pipe get the correct curvature at the rear. I bought 30 feet of copper brake pipe from a UK brake specialist. I bought a flaring tool from Frost and the ends. Made up a complete set of TC brake lines without any problems. Also, decided to add some armour spring protection for the rear curve. On the original set of brake pipes I removed, there was a nasty dent at this curve. Installed the pipes some time ago, and recently charged with Dot-5 brake fluid. No leaks yet, despite "maximum effort" brake pumping. Waiting for possible lock-on now! Regards, DAI --- JohnHWSteedman@aol.com wrote: > Fitting new copper brake lines to the TC, I've

> managed to flatten the tube > whilst I was doing the fiddly bit through the > chassis by the left hand three > way brass junction. The kink is only 3 "" from the > end of the pipe and I've > thought of heating it up and trying to force a > knitting needle through to > open it up. > > Any more scientific tips would be appreciated, plus > an explanation of how I > should have tried to bend it in the first place. My > plumbing manuals for > heating systems describe a spring insert, which is > pulled out when the bend > is complete, but I doubt whether that's the right > method for small bore > tubing. > > My thanks to the list in advance, > > John Steedman, TC0301 > > >

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[m.jablonski@mei.unimelb.edu.au]

John I agree with the others - don't try to restore the flattened tube. As for how to bend it in the first place - I had no problems forming the bends around solid cylindrical shapes of the approximate diameter, without using a tube bending tool. I've done this with both copper and steel brake lines. The line you flattened is the hardest to install, if it's at all too short you can end up flattening it on the sides of the hole in the chassis as you tighten the fittings, I think it's better to have a little extra length to allow the tube to pass through the chassis at 90 deg and "use up" the extra by little "U" shaped kinks on either side of the chassis. This also makes lining up with the connections easier. Remember to install a rubber grommet in the chassis to prevent chafing of the line. Mark Jablonski Melbourne Australia