How-to: Fabricating, Restoring and Repairing Hydraulic Brake Lines

In this in-depth how-to tutorial, viewers are encouraged to look over Moses Ludel’s shoulder as he replicates steel brake tubing on a rare classic car. Whether your DIY or professional shop’s project is an off-road rock crawler, a 4×4 truck restoration or a rare classic car in need of a pristine, original looking brake system, brake tube fabrication requires high standards and a professional approach.  Repairing and crafting steel brake pipes has become a regular part of automotive service work, and a growing list of professional and DIY/consumer level brake tools can now do the job better than ever!

Caution:  The HD 1080P video’s length is one hour and sixteen minutes.  When your favorite cable television series or live sports event is not airing, while the rest of the family slumbers, fix yourself a cup of coffee or tea (regular or decaf as required) and adjust your computer chair.  This how-to tutorial takes a while and for good reason:  your safety and the reliability of a braking system depend upon doing the job right!

 

This chassis project started with the typical rust and corrosion expected on a vintage car like a 1957 Chrysler New Yorker convertible.  Body and frame rust is common to neglected classic cars and trucks.  Brake tubing is also susceptible to rust.  The menacing use of salt and brine to de-ice highways can impact newer vehicles in much the same way, and brake work in cold climates now includes tubing replacement as an expected service procedure.  Loosening corroded fittings requires special care.  The small chain wrench shown can usually turn a stubborn flare nut loose without damaging its corners or collapsing the fitting. When parts must be reused, use the right tools.

 

These two tools of choice for this challenging, high stakes project were from S.U.R.&R.  The turret punch manual FT351 flaring tool is somewhat similar to other turret punch/adapter tools with die clamps.  The FT351 does a superior double-flaring job and leaves no marring or marks on the tube…Tested for the first time on this brake tube restoration project is the S.U.R.&R. PFT409 hydraulic pistol grip flaring tool. This flare tool offers the fast and repeatable flares attained by several other quality flare tools that we have tested.  Notably, however, where this tool moves ahead of the pack is the preservation and protection of the tubing shanks during the flaring process.  The PFT409 did not leave any kind of marks or blemishes on the tube while repeatedly forming optimal 45-degree inverted double flares on 0.028″ steel brake tube.  For restoring this car’s brake tubes, few other flare tools can meet the high standard of performance or quality finished look attained with the PFT409 from S.U.R.&R.

 

The S.U.R.&R. tube straightener is a cost-effective alternative to precision roller straighteners.  Careful use and a good eye or straight edge for referencing can produce excellent results at a fraction of the cost for high-end tube straighteners.  For those not doing a large volume of tube work, this tool will work well.  At right is the S.U.R.&R. RM69 inside reamer.  This tool is sharp and well shaped.  For our preferred inside and outside deburring, we use the tool available from Inline Tube.  The aim is a burr-free, square tube end with slight chamfers.  An outside chamfer helps the tube form against the punch adapters.

 

The most impressive and unique feature of the S.U.R.&R. pistol grip hydraulic PFT409 package is the smooth channeled dies (used with the smaller tubing sizes).  These dies do not leave a mark on 3/16″ or 1/4″ O.D. brake tubing.  Despite the smooth channels, the yoke screw clamping force is sufficient to prevent the tube from sliding.  Other manufacturers cut spiral or ring grooves in the die’s channel to prevent tube movement.  That approach mars and blemishes the shank of the tube, often nicking or cutting through the zinc electroplating on new steel tubing.  Damaging the electroplating can make original equipment style steel replacement tubing vulnerable to rust.  The number one cause of brake tubing damage (aside from physical pounding and tearing on a 4×4 rock crawler) is rust.  Why hurry the process along?  We opted for the S.U.R.&R. PFT409 for this critical and cosmetically demanding tube flaring project!

Tips on Using the SUR&R PFT409 Hydraulic Flaring Tool

If you choose hydraulic over manual flaring, there are many hydraulic flaring tools available.  The new SUR&R PFT409 tool set provides professional-grade results without marring or damaging 3/16″ or 1/4″ tubing.  Smooth channels on the 3/16″, 1/4″ and metric equivalent die sets will not mar up the tubing shanks.  Consistent, repeatable high quality flares are possible with the PFT409 tool.  Ease of use, handy size and exceptional reach for chassis-level work are key features.  Here are some tips for users wanting the right flare every time:

  • Straighten the tubing with the SUR&R tool before placing the tube in the die set.
  • Cut the tube squarely and be certain to deburr* the inside and outside of the tube end before placing the tube in the die set; uniform outside deburring will help funnel and shape the tube in the Op. 1 step.

*The SUR&R inside deburring tool is fine for inside deburring/chamfer.  See the Inline Tube TLF13 for both inside/outside deburring and chamfering.

  • Make sure the yoke spring-and-ball centering tension is correct. Square up (Op. 0) the tube with slight tension on the die blocks to assure that the tubing and dies are straight in the yoke.  Now tighten the yoke screw handle firmly by hand.  Keep punches aligned and centered with the tube end and die bore during Op. 1 and Op. 2. 
  • I use a coating of Millers Red Rubber Grease (caster based to prevent damage to brake rubber parts) on the Op. 1 and Op. 2 punch faces. This reduces friction and helps keep tube shape uniform during these two steps.  Millers Red Rubber Grease cleans up readily with a clean, lint-free rag, denatured alcohol, compressed air or a shop vacuum.  Any residue will not harm brake rubber parts.  Do not use petroleum-based grease.
  • On Op. 1, squeeze evenly and just to a firm, even point with the pump. Do not over-pressurize Op. 1.  The Op. 2 step can be made with higher pressure.  This approach will help prevent tube distortion and deformation during the first (Op. 1) step while also protecting the punch.  Experiment with spare tubing to find the correct pressures for Op. 1 and Op. 2.  I use Millers Red Rubber Grease as an anti-friction lube.

You can get consistent, quality flares every time by following these steps.  Forming a professional-grade flare the first time is critical when tubing is cut to length on the chassis with long tubing runs.  Always remove debris from flare ends when cutting hydraulic tubes or constructing hydraulic flares—on or off the chassis.  Keep metal debris, dirt and contaminants out of the hydraulic brake system!

 

Finished tube flares are a consistent 45-degree inverted double flare.  (This has been the most common flare type used in the U.S. although that traditional has yielded to DIN bubble flares in some applications.)  This 3/16″ size steel tubing bends properly with the correct bender.  The tight 180-degree return bends on this brake system are unusual and require both patience and the right tools.  The HD video tutorial, filmed at the magazine’s shop/studio, provides each step from a 25′ coil of bulk steel tube and a bag of new flare fittings to the finished and installed custom brake pipes.  When there is no pre-formed CNC replacement tubing available and the stakes are as high as this rare classic car, the right tools and techniques are crucial.  

 

 Installing the completed tubes requires use of a quality flare nut wrench like the X-Force design from AGS Company.  New replacement brake hoses should be installed with new retainer clips and fresh brake grade copper sealing washers.  These are inexpensive measures, and the clips are available from Dorman, Summit Racing and other vendors.  Quality brake parts sources can provide copper brake hose junction washers.  Once tubes and hoses are firmly in place, all fittings and hose connections should be torqued to specification.  A set of crow’s foot tubing flare nut sockets is valuable and available for this final step.

For more details on the S.U.R.&R. PFT409 hydraulic flaring tool and other brake service tools visit:

https://www.surrauto.com

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