Posts Tagged ‘Bending brake lines’

Bending Brakes lines – TIPS

Monday, April 18th, 2011

Bending Brakes lines – TIPS

Here we are in the middle of April and guess what?  It snowed this morning, leaving a nice white blanket of snow on the ground.  Boy, Mother Nature is having a great bit of fun with us this spring.  Hmmmmm, what happened to global warming?  Oh well, we can’t do anything about the weather, but I will show you how a created some very nice and exact brake line bends.

The 1929 Model A Ford Roadster hot rod is using C4 Corvette suspension and brakes.  The parts all came from a 1986 Corvette Indy Pace car convertible that met with an unfortunate ending, rendering the car to the world of salvage.  The good thing from this sad event is that every part that I did not want or need was sold, including a wrecked shell of the body.  A tidy bit of profit from this venture was now on the table.  That would be re-cycling in this day and age at its best.  The 1986 Corvette uses the metric ISO bubble flare on its brake line tubes.  Wanting brakes lines to look good on an open wheeled high boy roadster hot rod can be a bit of a challenge.  Nice tubing bends and exact fitting lines are the fine bits of detail and do require patience and time.  In another post, I will show you how to make perfect metric ISO bubble flares.

Bending brake lines and fitting them on the car is a real craft.  I found that the process can be simplified if I made a mock up of the brake line before bending the actual tubing.  For this I using 0.125 inch ( 1/8th”) wire.  This can be purchased from any farm supply or fencing store.  I had the good fortune to have a roll of it left behind by the previous owner of the Victorian house I bought many years ago.  This gauge of wire cuts and bends very easily.   When you are underneath the car in tight areas, this is an important feature.  Having several very complex bends to make, the mock up of the brake line became an invaluable tool for me.  I found that without the wire mock up, my success rate was 50% for an exact fit and placement.   Wanting a more perfect set-up and installation, I quickly realized that a formed pattern would make the job easier.  After employing the mock up, every single brake line fit perfectly the first time when it came to installing them.

Start off with wire slightly larger in length then you think that will be required for your brake line pattern or mock up.  The wire does come on a roll and will need to be straightened before you start.  You can straighten the wire in the bench vise or just use a ball peen hammer on a steel table.  I used both to straighten the wire.  This only took a couple of minutes to complete.  If you can’t find this type of wire, why not use an old metal coat hanger, or for short brake lines, or even welding filler rod?

Start at the receiving end of the first brake line fitting on the car.  For example the end of the rubber hose from the brake caliper to the frame, I inserted the wire into the tube opening.   Be very careful to only insert it far enough to simulate the actual brake line connection.  A socket was selected from the tool chest having the same diameter as my tube bending tool.  I found the using a socket as a bending form for the wire was easy to handle while underneath the car.  Depending on how long the brake tube needs to be, I might even use a few spring loaded clamps to hold the wire in place on the frame of the car during the forming process.  Once I am completely satisfied that the brake line shape is a desired one, I remove the clamps if any were used and measure the length of the wire.  I add 0.25 inches (1/4”) times two for the flare on each end of the tubing.  Remember, measure twice and cut once.  On some tubing I only needed to add the extra for one new bubble flare (0.25 inch) as I was shortening a pre-made brake line.  

Some time ago, I purchase for about $25 an inexpensive double flaring tool kit.  This was by no means a great kit.  As with most things that come in off shore, the quality was not great but good enough for the job I required it to do.  The kit did have a small tubing cutter. 

Using the tubing cutter from the kit, I cut the tube to the correct size.  In order to make the task a bit easier, I purchased pre-made lengths of tubing with metric ISO bubble flares and new fittings from NAPA.  Using tubing from a 25 foot coil took a bit of time to strengthen and I still needed to purchase new fittings.   That was fine, but I found that the already straight lengths with new fittings from NAPA saved time.

Once the tube has been cut to size, the cut opening should be de-burred.  You can use the de-burring tool that comes with most kits, but I found using the wire wheel on the grinder worked just as well and was less frustrating to use.

Using the wire form, I now carefully re-create the bends using a hand held tube bender.  I use a special set of vise grips that I modified to have a wider flat gripping surface to clamp the tubing to the bender.  This is especially important for smaller brake lines that do not have much to hold onto while completing the bend.  Using the clamp prevents the tubing from moving during the bending process. 

Before making your last bend on the tubing, install the new brake line fitting correctly making sure it can move into place once the bend is complete.  Brake line fittings will not move around or slide over bends.

This is a difficult process to explain, and watching the video below should clear up any questions you might have.

 Fast Tube
Fast Tube by Casper