With new front suspension, new rear suspension, plus brake parts and plumbing from the original truck that were right at 50 years old, the decision was made for me.... Rework the brakes !!!

My previous knowledge of brake systems included changing the pads or shoes and rebuilding the cylinders, but never building a complete system. My education was just beginning. What I've learned and what I've done is documented here in hopes it will help someone else.

I thought it best to break this project up into sections, first the master cylinder and booster, then the lines and finally wheel units. Since I have 4 wheel disc brakes now, this article does not cover drum brakes or split systems with drum rear and disk front and their associated cylinders, etc. Obviously some of the data will be helpful for those systems..tubing bending, flaring, etc. Another excellent technical source is the C. H. Topping site at http://chtopping.com. Their owner, Vince Bunting, knows his brakes and has compiled a really great site with easy to understand brake knowledge. Check it out.

Master cylinders

I began by reading all I could find on brakes, and there is a LOT to read. A good portion of the information deals with racing applications which are totally different from street trucks or cars. Using racing parts might seem like a good way to go, but it might be the wrong decision for a street application. These systems are two different animals that do things in two different ways.

Brake systems are nothing more than small hydraulic systems and the piston size, line size, pedal ratio, wheel cylinder or caliper size are all part of the equation that determines pressure on the pads, pedal feel and travel and of course braking efficiency. The calculations aren't terribly complicated but all these factors must be considered to build a safe, efficient braking system. I think we'll all agree how much that is worth when you're cruizin down the freeway at about 85 and that little blue haired old lady merges in front of you at 28 mph, squinting through the steering wheel, arm out the window and the wrong blinker on.

I knew from the beginning that I wanted power brakes, so when I bought the Volare clip I told the man that I needed the power brake booster and master cylinder that went with the front suspension no problem and no charge. But, after more reading, I wasn't sure that my Mopar master cylinder would have enough pressure or volume to operate the Lincoln calipers in the rear. Since this is such a hybrid, I couldn't find anyone locally that could give me any knowledgeable help with my questions. Calls to local brake 'experts' were usually acknowledged with "I ain't ever heard of nothin like that wadya say you was building ?" I had talked to other brake component suppliers across the country, but none that could give me definitive answers about my mix of parts. I finally located Vince Bunting at C. H. Topping and Company in Long Beach, California (email -- [email protected]). Vince has done several 'hybrid' systems and was very knowledgeable about what it takes to make it work, plus he is not so interested in how much he can sell a rookie. His interest in making it a safe, responsive system got my business, not his flashy ads or racy logos. Their web site holds a wealth of knowledge on braking systems, both racing and street applications. It's very much worth the hour or so you'll spend reading.

After describing what I was trying to do and with which components, Vince asked several questions: What size tires?, vehicle weight?, engine size?, front to back weight distribution?, and use of vehicle? He also needed to know caliper diameters for front and back units. With my answers and his background he was able to size the master cylinder to the job.

I already had the vacuum booster from the Volare. He asked about its condition and suggested that he could check it out and adjust the stroke after mounting the new master cylinder and combination valve. I sent the booster to him, where he rebuilt and tested it. Then he added a Corvette Master Cylinder to the booster. Vince calculated that this cylinder has the correct size bore and stroke to give me the pressures and volumes I need to operate both the Volare front calipers and the Lincoln rear calipers.

A combination valve was attached underneath the cylinder mounting bracket. It contained the correct valving to make the brakes work properly ...see paragraph below on combo/residual/metering valves) Vince also twisted up the connecting tubing so it was a finished unit, ready to install when I received it. Here's a pic of the installed unit.

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Since I was using the original hanging pedal assembly from the Chrysler product that gave up its front suspension, the pedal linkage matches perfectly to the master cylinder and everything works smoothly and easily.

Whatza combination valve ? Whatza Metering Valve ? Whatza Proportioning valve ?? It all sounds confusing when you're just beginning to do this stuff and several people have different ideas but here is what I found out from Vince and it was verified by other sources

A proportioning valve is used on cars with a front disc/rear drum system. It controls the amount of pressure on the rear half of the system to keep the drums from locking up as the weight of the vehicle is transferred to the front. It is installed in the rear brake line.

A metering valve is also used in a disc/drum setup. Its purpose is to slow the application of the front disc till the rear shoes can contact the drums. This way all the braking surfaces make contact at the same time.

A combination valve is just that a combination of a proportioning valve, a low brake pressure warning light and a metering valve. It also provides you a common place where all the brake lines get connected.

The last is a residual valve. These are used only in systems where the master cylinder is lower than the wheel cylinders. They're usually seen in low street rods and trucks with the master cylinder under the floor boards. You don't need them if you have a firewall mounted master cylinder.

I'm not suggesting that you have to use a Corvette master cylinder with a Chrysler booster for your truck but what ever you choose, I suggest you call Vince and ask him about the feasibility of your proposed system.

Brake lines

So now with a major component configured and mounted , the next component to be considered is the lines.

First let me say that if you are doing a completely stock restoration, there are companies that have computer designed pre-bent lines ready for sale. You can buy them in standard steel or fancy stainless steel depending on your budget of course. Check the truck and street rod magazines for vendors. Inline Tube is one (http://www.inlinetube.com) Classic Tube is another (http://www.classictube.com). Inline was very helpful with my hoses and fittings reasonably priced and shipped quickly. If I had gone the restoration way, I think I would have chosen the pre-bent route. It's quick and easy and probably less expensive, especially after you waste two or three joints of tubing bending them wrong or forgetting to put the fitting on BEFORE you make your flare. Ask me how I know this. Another advantage of pre-bent is the money saved from not buying a bender or flaring tool. You're probably talking between $50 and $100 for a decent set of tools for brake line work, so factor that into your decision to consider pre- bent lines. (In my case buying the tools is a good reason to do the project you can never have enough tools !!!) But, keep in mind their speciality is stock replacement systems. I'm sure they could bend up a custom set with enough specifications and patterns from you, but that is an expensive way to go.

My truck has a Chrysler front clip, a Lincoln rear end, a Corvette master cylinder with a Chrysler power booster.. don't look you won't find that system in the catalog.

Plumbing the Lines

It's a really good idea to sit down with a pencil and paper and draw out your system. Start at the Master Cylinder connections and plot the routes, lengths and type of fittings you'll need. Don't forget the additional components like, proportioning valves and brake light switches.

Brake tubing comes in standard steel and stainless steel. Forget copper, aluminum or fuel line tubing it's not made for the pressures of brake systems. Don't scrimp here on cost.

Before you start plumbing, there are some choices to be made. One of the first is deciding if you want to use plain steel lines or stainless steel. For most 'drivers' the plain steel lines will work for you. They have been used for years on every car that rolls off every assembly line in the U.S. and many of the imports. If you're building a show truck and need shiny then stainless lines can be bent and polished to make it pretty. Although, plain steel can be cleaned up with a Scotchbrite and sprayed with clear finish and made to look really good also.

The major difference in the two as far as installation is the type of flares required. Plain steel lines use a double flare (45° with a standard inverted flare fitting, in either brass or steel. The stainless lines use a single flare (37° and AN style fittings. Also, stainless is harder material and a little more difficult to work with.

The other point to consider is how often you will make changes, service or otherwise break the connections. The double flare type joints, used on plain steel lines, do not hold up well to repeated loosening/tightening cycles without leaking. They are made to be torqued down properly and left till the millennium without leakingō and mostly they do, unless damaged. If you foresee a lot of changes in your system or frequent service, I'd suggest using stainless with the AN fittings. AN fittings (Army/Navy) were designed by the military for aviation systems where components are added and removed with some frequency. They are used almost exclusively in the racing areas for just that reason.. multiple service cycles. So, make your decisions accordingly.

You can buy your tubing stock in a roll or in cut/flared/fitted lengths. The prepared cut lengths look neater (straighter) than the roll stock but neither is better, unless you consider the number of joints that might cause leaks. I used the pre-cut lengths and bought them long enough so that I would have to cut some off at each of the junction points anyway while I did waste some tubing, I saved making one flare with each stick used. The tubing comes in lengths starting at less than 1' and up to 6' in 1' increments so you should be able to buy in lengths close to what you need with little waste. It's a good idea (really a necessary step) to use some type of pattern for the complicated bends. I used brazing rod, but you can use coat hangers, tie wire, anything that will hold a shape. Leaving the master cylinder and routing down the firewall and into the frame rail is a little tricky using your memory I have some pipe fitting friends who can do this by just looking at it and it fits like factory when they finish. I can't, most people can't either. The pattern method is fool proof if you make your pattern carefully and PUT YOUR FITTINGS ON FIRST !!

Another practical tip after you're sure your fitting is on the tube before you flare make sure the threaded end is toward the end of the tube AND make sure your fitting is at the correct end of the tube before you make that first bend. Fittings have a way of sliding up and down the tube. When you're ready to make a bend, make sure your fitting is down at the flare and hasn't slid up past your bend point.. it's frustrating, believe me. It's a good idea to take a piece of masking tape to keep the fitting in it's proper place. Again, don't ask me how I know !

So you have your pattern and you're ready to bend the tube. What's next..???

Bending the Tubing

First. If you're really good you can cut before you bend, personally I make all the bends, take the finished tube to the installation site and then mark my cut point.

Buy a good quality bending tool that uses mandrels to hold the shape of the tube while bending.. the mandrels prevent crimping . Forget the spring type benders, they are for soft copper tubing. Consider the intricacy of your bends when you shop for a bender look at the mandrel and its diameter. You can't make a turn with a 1" radius if the head of the bender is 2" That's why I like the second bender below it has a small mandrel and will make a 180° end with about a 1" radius.

	This is a single bender with interchangeable mandrels it works well but is limited by the radius of the mandrels and the complexity of the bends it can make.
	This and the next picture are single benders the one at left is for 3/16" tubing and does an excellent job.. it has a movable hook that holds the tubing in place as you bend, degree markings on the body of the bender.. this is my favorite bender
	This bender is basically like picture #2 except for a larger size tubing.
	If you find one of these benders make sure there is a mandrel small enough to do 3/16" tubeųome only go down to 1/4" Watch your sizes when buying
	I've never been able to use this type on anything but soft copper and nothing smaller than 3/8" without crimping it. Might just be me though !

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Here is a picture of the bender I like finishing a 90° end in 3/16" tubing. This also shows about the shortest bend you can make and still get a fitting on and do a flair about 1-1/2".

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A tube bender is a tool you have to learn how to use properly. There are degree markings on the side of the mandrel and the base that tell you when to stop for a 45°, 90° end; there is also 0 and an "R". If you line up your bend line at the "0 the radius bend will start there and extend through the curve of the bend. If you line up your bend line at the "R", that line will be in the radius of the curve.. it can make a difference in the line length. Buy a little extra tubing and make some trial cuts.

There was an article in Street Rodder Magazine that suggested making several template bends and using them at your turn points to mark your tubing correctly for the bends. Whatever method you use, practice a little before you do your final turns to get the best results.

Cutting the tubing

O.K. you've made some beautiful bends and mastered this tool, but the tube is still too long you need to cut it off.

Another practical tip.... The old carpenters rule applies here. "Measure twice, cut once". You can make it shorter, but you can't make it longer if it's wrong.....I've never seen a reliable tubing stretcher.

To make your cuts you need a tubing cutter. Do not use a saw. You want no residue or metal sawdust, and the double flaring tool will not work well unless the tubing is cut perfectly square. You can get tubing cutters at any auto parts store, Sears, or Wal-Mart, generally for less then ten dollars. It's the same tool used to cut copper tubing for plumbing. It makes a nice square cut.....leaves no residue and has the attachment to de-burr the tubing after the cut. That part is important.

Typical tubing cutters.

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fancy chrome mode	good for tight areas	Wal-Mart standard

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Here is how they work. Insert tubing and line up cut mark under the cutter wheel tighten screw gently and rotate the cutter around the tube.. tighten more.. go around tube again repeat until you have two pieces. The pointy thing on the back of the cutter in figure 1 is the reamer. After the cut.. stick this in the end of the tube and ream the edges back this deburrs the cut and assures that the tube is open to it's full diameter.

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figure 1	figure 2

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Now so far, the bending hasn't been too bad.... you probably messed up a few feet of tubing but hey, that's how you learn. The guys at the parts store had to reorder for me !! The cutting is straight forward and hard to screw up. Even I figured out that part fairly easily. The next step is a little more complicated and much more important.

Flaring the lines

Plain steel brake lines use a "DOUBLE" flare, not the normal single flare you'd see in copper gas piping. Stainless steel uses a single flare but not a 45°flare it uses a 37° flare. The single flare is due to the hardness of stainless and the fact that it is not seamless tubing it's small but you can see the seam if you look.

Double flaring tools and the 37°tools are more expensive, between $40 and $90 depending on where you get them. You can not use the same tool for both flares/

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Typical Flaring Tool Kit

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Flaring is straight forward and not nearly in the rocket science area if you just exercise care and a little precision.. After your initial setup, the tool does all the work. Double flares are done in three steps. First, the tubing is put into the clamp and set at a prescribed height. Next it is pressed with a die to spread it into a "bubble" shape. If you stopped right here you would have the "bubble" fitting that is used on import cars and beginning to show up on American cars as well. But since we aren't dealing with LBCs (Little British Cars) we'll finish our 45° double flare. After the bubble portion is complete, remove the die and repress the tubing with the 45° press this completes the double flare. Slide the fitting up against the flare and check the fit.

Now we'll do the details with pictures

First, after you making the cut with the tubing cutter, and reaming the inside edge, chamfer the outside edge of the cut. You can use a file or a dremel tool and just take the edge off slightly. Next (making sure you fitting is on the tube and positioned with the threads toward the flare) insert the tube into the press and extend it to match the height of the base of the die that makes the bubble portion of the flare see Figure 3 below

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figure 3

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The next step is to flip the die over and insert it into the tubing, attach the press to the base and do the first part of the flare. (See Figure 4 and the completed bubble in Figure 5)

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figure 4	figure 5

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Next, back off the press until you can remove the die. Ŵhen screw down the 45°press. (Figures 6 & 7) Tighten the press until you feel good resistance and you're finished

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figure 6	figure 7

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This completes the flare pull your fitting down and check it's fit. You don't want any crooked flares or flares that aren't perfectly round (no oblong flares, please) This is the sealing surface for your brake lines if they aren't good They'll leak..and you don't want that.

Routing the Tubing

Your main tubing lines will leave the master cylinder and by some route get to the wheels. Mine ran from the master cylinder (actually the combination valve) back to the firewall.. down the firewall to the frame rail. The rear lines continued to the rear, the front turned and headed the other direction. The piece of tubing I bent from the combo valve for the back lines ended just after I got it into the frame rail. This seemed like a good place to plumb in the brake light switch. I plumbed in a tee and screwed in the hydraulic brake light switch at this point..(Figure 8) from there it was a straight shot back to the rear cross member.

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figure 8

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I'd suggest that your route be protected from damage and from as much heat as possible. Also, consider other items that might be added to your truck later and the holes needed to mount them when choosing your route. I tried to tuck mine into the frame rails and as high as possible in the corner. There's less chance of road debris hitting them and they're reasonably protected from exhaust heat, drill bits, etc.

Don't forget your accessories in the lines. If you're using a hydraulic brake light switch or proportioning valve in the rear lines, don't forget to plumb it in. All your lines should be secured with line clamps to prevent any vibration. Vibration = abrasion, abrasion = failure, failure = scary rides and really un-pretty stops. Use clamps every 12 - 18" at a minimum.

Lines usually terminate in some type of bracket or fitting to which your flexible hoses connect. This can be a simple tab welded to the frame or through frame connectors. But something stationary is needed for this connection.

The rear line usually runs down the frame rail and turns a 90° angle at a cross member near the rear end (figure 9). At this point you can either install a tee and run to each side of the frame with separate hard line or you can run a flex hose from this point to a tee fitting on the rear axle then hard line to each side attached to the axle itself (figure 10,11 & 15). Either route you choose will get you near the calipers and the hard line will be terminated in a bracket at this point. (figure 12) Here again, a simple tab with the appropriate sized hole and a line clip is all that is necessary. You can fabricate these tabs from 1/8" x 1-1/2" flat stock with the correct sized hole drilled in it, or you can buy them pre-made from a supplier like Inline Tube for about 75 cents a piece. Look at the pictures below.

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figure 9	figure 10
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figure 11	figure 12

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From the tab on the axle housing (or the frame rail depending on your route), install the proper connections and fittings to attach your flexible lines to the calipers. (Figure 13 & 14) Stainless steel braided hoses aren't absolutely necessary. Stock lines will work just as well. In my case with the Lincoln rear end, the stock hoses cost more than stainless hoses and didn't look nearly as neat.. more pics below. On my calipers, the hoses terminate in Banjo bolts and fittings. When you install your flex hoses, move the suspension through its entire travel to make sure the hoses don't bind or rub on moving parts. You can put a half twist in the line to give it enough curl to make it move out of the way when suspension moves. (figure 16)

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figure 13	figure 14
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figure 15	figure 16
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figure 17	figure 18

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The front lines follow the same route as the rear down to the frame rail. (figure 19, 20 & 21) Then turn and head toward the front of the truck. I used through frame connectors for the front lines and a short run of tubing to the left front connector and a 90° to connect it. There is a tee in the line at the frame rail and the line for the right side runs beside the boxed frame rail, turns across the front cross member and back the right rail to the through frame connector.(figure 23 & 24) Stainless steel hoses connect to the other side of the connectors and attach to the calipers with banjo bolts.

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figure 19	figure 20
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figure 21	figure 22
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figure 23	figure 24

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Since everything I've done so far has to come off to paint the frame, all my plumbing is loosely fitted and none of the connections have been torqued down. The final step will be to tighten everything put on the line clamps add the fluid and bleed the system. I'm a good piece away from that just yet the engine block is still on the stand and there is much more to be done before testing my work. But, I feel like I've accomplished something big just by getting the brake system done.

This by no means covers all the details of designing a braking system and I didn't detail the mounting of the master cylinder although I might add it later. I've tried to make it as straight forward and simple as I could.I hope some of you find this useful in your projects.