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1949 Chevy Brake Lines - Flaring UpFlaring And Bending Brake Tubing The Right Way From the January, 2010 issue of Rod & Custom By Kev Elliot
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With all the major mechanical components installed in our '49 Chevy project Purple Pig, it's time to get down to all the little jobs that seemingly take forever in order to make the car road worthy. One of the larger of these "little" jobs is the time-consuming task of running brake lines. We already installed the ABS Power Brakes master cylinder (July '09 issue), and used a Straight Brake Line kit from Inline Tube to hook everything up. While Inline Tube offers pre-bent kits for many applications, they don't have patterns for every combination, and suggest using their Straight Line kits for custom setups like ours. Of course making our own lines meant we had to cut, bend, and flare the brake tubing. Classic Performance Products (CPP), in addition to offering suspension and steering components, has a wide range of brake parts and systems, and sells a great Deluxe Dual Flare tool kit at a reasonable price, which we used for our installation. We also used a 16-inch stainless flexible rear brake hose from CPP to match the similar hoses that were supplied with our Chassis Engineering front suspension. With all our parts and tools gathered together, all that remained was to wait for a slot to use the Backyard Buddy rack at our Source Interlink Tech Center, get the Chevy up in the air, and start bendin' tube. Here's the double flaring... Here's the double flaring tool kit we got from Classic Performance Products. We already had a basic flaring tool that is clamped in a vise and seems to need three hands to make it work, so this handheld version was a revelation. It's not foolproof though, as its ease of operation can cause concentration lapses! Before any bending could start though, once under the car we spent some time planning where we'd route the tubing. This is especially important in areas like the rear axle, where clearance for suspension components, as well as full suspension travel, comes into play. Keeping the brake lines away from the exhaust is also important, as well as planning where the exhaust will run if you're like us and haven't fitted the system yet. At the front, we re-installed the steering shafts and U-joints that we'd removed when we filled and painted the firewall, in order to ensure we routed the brake lines well away from the rotating shafts. Again, pre-planning where the exhausts would run from the headers meant we could plan the brake plumbing route. Inline Tube supplied this... Inline Tube supplied this steel, straight brake line kit, shipped in a tube, as it includes four 6-foot straight lengths, complete with fittings, and 45-degree double flared ends already formed. The steel tubing is coated with a tin/galvanized rust protection, just like the OEM original. Also included are spring wrap, stainless line clamps, inverted flare unions, T unions, and proportioning valve fittings. The straight tube meant we didn't have to straighten a coil of tubing, and we found no lines on our Chevy would be longer than 6 feet anyway. If you've never flared brake tubing before, we'd suggest reading the instructions and making a few practice flares before tackling your lines, though the CCP flaring tool was simple to use. Work slowly and methodically, and once you get your head around how to bend the tube, and don't bend it the wrong way on long lines with many bends (believe us, it's very easy to do if you're not concentrating), forming perfectly fitting lines can be very satisfying.  There are various tube benders...  There are various tube benders available, but we use these tri-bender tools, as each one can bend three different diameters of tubing. The smaller bender handles 3/16-inch tubing, and can perform tight bends. Both benders will bend the tubing slightly more than 90 degrees.  The combination valve is so...  The combination valve is so called because it contains a metering valve, which allows the rear drums to engage just before the front discs, a pressure differential switch, and a proportioning valve to reduce pressure to the rear brakes, preventing rear wheel lockup. We tapped the chassis and mounted ours close to the master cylinder.  As we'd previously installed...  As we'd previously installed the ABS Power Brake master cylinder, the first tubing we bent was one of the lines running from the master to the combination valve. You can see we've already formed two bends, and are marking the tubing where we want the third bend to finish, in line with the master cylinder port.  To bend brake tubing, it is...  To bend brake tubing, it is placed in the groove in the bender that corresponds with the diameter of the tube. As the handle is pulled around, the "arm" at the top holds the tubing in place. To form the bend in the correct place, the red Sharpie mark is aligned with where the tubing will ultimately end up in the groove on the curved section of the bender once it's bent.  Tubing cutters are available...  Tubing cutters are available in various qualities, from the cheap $3 version on the right to the larger version that was included in the flaring kit from CPP. Inline Tube doesn't recommend using cutters, as a dull cutter will harden the end of the tube, making flaring difficult, and instead suggests using a metal fiber cut-off wheel. However, we lubricate the cutting wheel every time we cut brake lines and have experienced no problems over the years.  To cut the tube, it's placed...  To cut the tube, it's placed between the two rollers in the tool, and the cutting wheel gradually tightened down as it's rotated around the tube. A few rotations will see the tubing cut and ensure that you don't apply too much pressure at once.  Once the tube is cut to length,...  Once the tube is cut to length, this deburring tool on the CPP cutter can be used to deburr the inside of the tube, which is important for a good flare.  The CPP flaring kit also includes...  The CPP flaring kit also includes this handy gadget for deburring the inside of the tube, and flipped around will perform the same job on the outside.  Before you begin to flare...  Before you begin to flare the end of the tube, remember to install the threaded fitting, as it can't be done afterward. (Yes, we omitted to install it in these demonstration pictures!) The tubing is slipped through the appropriately sized jaws in the flaring tool, and should extend beyond the surface to a distance determined by the step on the correctly sized adaptor. The flaring tool should then be clamped shut by closing the handles.  This is the adaptor with different...  This is the adaptor with different sizes for different diameter tubing. The 3/16-inch adaptor is on the right, with the step mentioned above clearly visible.  With the tubing extending...  With the tubing extending the correct distance, and the stem of the adaptor placed inside the tube, the bridge is swung into place, its securing nuts tightened, and the T-bar tightened so the conical head is forced into the depression on the adaptor, pushing the latter into the tube.  With the adapter removed,...  With the adapter removed, it can be seen that the end of the tube has been formed into a bell shape.  The conical head is again...  The conical head is again tightened, folding the bell shape in on itself to complete a 45-degree double flare. Don't tighten the head too much though as you'll crush the end of the tube. Experience will teach you how far to tighten the head.  Here's the completed double...  Here's the completed double flare on an actual piece of tubing we formed for our project Chevy. Note this time we remembered to install the fitting before forming the flare! It should be noted that you can't form a bend in the tubing too close to the end, with a minimum distance being the length of the fitting plus the depth of the flaring tool's jaws, plus the amount of tubing that extends through the jaws required to form the flare.  We used the spring wrap included...  We used the spring wrap included in the kit from Inline Tube to offer some protection for the brake tubing in certain areas, such as where it runs under the chassis to the front flexible hoses. We found a cut-off wheel ideal for cutting the sprung steel wrap, installing it first on the tubing then pulling it back slightly for cutting level with the end of the tubing.  Of course the spring wrap...  Of course the spring wrap has to be installed before the flare is formed at this end of the tube, hence pulling the wrap back to allow room to fit the tubing in the flaring tool as well as sufficient room to install the fitting.  Our Mustang II-based IFS was...  Our Mustang II-based IFS was supplied by Chassis Engineering with a pair of braided stainless steel flex hoses, mounting brackets, and retaining clips, which we matched up with a similar 16-inch braided hose for the rear from CPP, supplied complete with T union and mounting bracket.  Here's our completed, and...  Here's our completed, and wrapped, brake line leading from a T union on the inside of the chassis to the braided flex hose at the left front wheel. We used the stock Chevy mounting bracket, and temporarily held everything in place by fitting the retaining clip backward, as we'll have to remove these components at least once more before they're final fitted.  The tubing that runs from...  The tubing that runs from the left chassis 'rail, across the front crossmember to the right front wheel has to be one of the most complicated we've fabricated, and knowing it's impossible to check every bend when dealing with a 6-foot length of tubing-and this section turned out to be a mere 4 inches short of that-as you can't physically get it into all the spaces it needs to go into while forming all the bends, we opted to make a couple of patterns to copy. Here's the pattern for the left side, next to the final formed tubing.  The completed front section...  The completed front section looked like this once finished. Shown here upside down, it uses two sections of spring wrap in sensitive areas, namely where it passes under the chassis and where it passes close to the steering universal joints.  Here's our completed, and...  Here's our completed, and wrapped, brake line leading from a T union on the inside of the chassis to the braided flex hose at the left front wheel. We used the stock Chevy mounting bracket, and temporarily held everything in place by fitting the retaining clip backward, as we'll have to remove these components at least once more before they're final fitted.  It's always advisable to use...  It's always advisable to use a "flare nut" or line wrench when working on brake lines, as a regular wrench will easily round off the fittings, especially when they're old. The gap in the end of the wrench allows it to be slipped over the brake tubing to apply force to all six faces of the fitting, eliminating slippage.  Sometimes it's unavoidable...  Sometimes it's unavoidable that you'll have to join two sections of tubing. The Inline Tube kit includes these inverted flare unions for just that purpose. We had to make our rear brake line in two sections and join them above the C-notch in the chassis, as it was physically impossible to run a single line in the route we chose (through a gap in the bracing for our C-notch), necessary to avoid suspension and exhaust contact with the brake tubing.  Looking down through the removable...  Looking down through the removable floor section above our rear axle, you can see how we chose to route the CPP flex line in order for it to be able to move through the full range of suspension travel without rubbing or binding on the bodywork or suspension. We fabricated a small bracket to bolt it to the third member, and now just have to run tubing across the top of the axle tubes to each wheel cylinder.
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