tof

Exactly. With traditional port fuel injection the backs of each intake valve is washed by gasoline every time the injector squirts gas into the intake runner. Direct injection has performance and efficiency advantages under some driving conditions.

I like the solution employed by Toyota and Lexus. All their engines use both direct and port injection, switching between the two as needed and providing the best of both systems with none of the drawbacks of either.

Kyras

Really? That's good to know. I may go to Toyota for my next daily replacing my Pilot. I hope it's good to go now.

poorshoeless

Stay away from the early Lexus IS250/350, they have direct injection-only engines.

dlq04

One of the main brake lines on my MGA is copper. This is what one internet source said . . Are copper brake lines safe?
After disproving myths related to brake lines, we would like to show that copper lines can be used in brake systems. They are the standard value replacement of steel lines if they meet all the aspects listed above and the technical requirements.

Scooterboy

It finally happened. My Laguna Blue S2000 has been totaled.

Now I have to want for the check!

cosmomiller

I had no idea about copper/nickle alloys. This is what happens on a rainy day when you go down rabbit holes on the computer.

The Truth using About Nickel Copper Brake Lines

A few years ago, I was introduced to a wonderful world, rustless copper and nickel tubes, brake lines. I think these things are great, but how good is it, really?

The article was originally published on December 8, 2017.

In the rust belt of the United States, the service life of steel pipes often used for braking and fuel pipeline of household automobiles is very limited. It can rust and leak in just ten years. Repairing rusty parts (or entire lengths) with new steel pipes can be a bit of a hassle, especially if you make your own wiring.
Another option is to buy pre-bent pipelines, which are expensive to purchase and difficult to transport, and sometimes require the removal of major components (such as fuel tanks) to install.

If they are (non-stainless) steel, you can expect to replace them again in ten years, just as you made them yourself. Of course, you can buy some time for yourself by using polysteel coatings, but in the salt state, this will only give you limited time compared with the rusty choice.

If you really want to solve the corrosion problem once and for all (rather than in a more friendly climate), there will always be stainless steel pipes. However, in addition to higher costs (which may be worthwhile in the long run), stainless steel is difficult to process due to the hardness of the material. It’s not as easy to bend, burn or seal as ordinary steel (that’s not to say, ordinary steel is a walk in the park).

Copper-nickel tubes, such as Cunifer or Nicopp, offer a seemingly miraculous choice. Although it is arguably a softer material than steel, DOT is approved for hydraulic applications. In fact, its psi rating is only slightly lower than that of steel and is still strong enough to brake, usually in the range of 800 to 1500 psi. (In some cases, the figure may be as high as 2000.)


But the main attraction here is the corrosion resistance of the material. Copper and nickel tubes do not rust. It does oxidize, but it does not produce catastrophic rust like steel.

If that’s not enough, then soft materials make it a dream. It’s much easier to form, and if you’re careful, you can even bend the pipe with your hands without curling or restricting it. It burns easily and is easily sealed when fastened in place.

But you have to pay for it. Depending on where you buy nickel-copper tubes, nickel-copper tubes can run higher or lower than stainless steel tubes, but they are always much higher than cheap low-carbon steel. But when you look at the work ahead of you and the potential life of the tubing, higher costs quickly become insignificant.
(Speaking of life, I’m surprised to find that copper and nickel tubes have been used in some European cars since the 1970s! And it’s well supported in its age.
Sounds great, isn’t it true? You are not alone. Visit any online message board that discusses these things and you will find that people automatically suspect using anything softer than steel. They say it’s not worth the risk of failure. After all, imagine the consequences of losing the brakes. Or fuel leaks!
However, when discussing these issues, it is important to understand the materials, advantages and disadvantages, and consider their applications. Just like the wheel bearings of some vehicles are fixed by grooved nuts. When it comes down, its entire wheel of the car is eventually made up by…. Cotter pin! This does not mean that the car itself is unsafe, nor does it mean that the cotter pin needs to be made of hard material. Even when it comes to security, there is something “good enough”.
It is also worth mentioning that some of these discussions have revolved around the word “copper”, which makes you wonder if we are still talking about copper-nickel tubes, or just plain copper, and you don’t want to use it to do such things. The content of nickel, iron and manganese in the alloy is the key component to improve road performance and fatigue (and general) strength.

But there’s another line of reasoning against copper that caught me by surprise. They call it “copper corrosion”, which has something to do with ions and the metal breaking down from the inside.

But there’s another line of reasoning against copper that caught me by surprise. They call it “copper corrosion”, which has something to do with ions and the metal breaking down from the inside.

At first glance, there doesn’t seem to be a whole lot of information out there about it. It’s something different from moisture contamination. Unfortunately, articles on the subject range from long-form sleep-inducing technical gobbledygook to what almost comes across like a fearmongering upsell opportunity for shops to increase their profits. Thanks to the limited information available, skepticism about this interior corrosion runs high, especially in this thread.




But wait..... There is more:

Are Copper-Nickel Brake Lines Safe?

DECEMBER 16, 20210 COMMENTSRumors about the questionable impact of copper and brake lines continue. But today, there is no longer a reason for the negative connotation. We are no longer living in the mid-1900s.

So are copper-nickel brakes lines a good thing today?

Today's copper-nickel brake lines exceed the quality of stainless steel brake lines. This article will update you on the latest in copper-nickel safety and success.

What is Copper-Nickel Brake Lines?

In the olden days, copper brake lines were a hazard waiting to happen. In 1965, brake lines were the cause of 251,000 car accidents. The Society of Automotive Engineers determined the corrosive deterioration of the steel brake line was at fault.

The industry switched to brake lines made from 100% copper. These lines burst from the pressure causing even more accidents. People demonized the copper brake lines.

Fast forward into the new millennium. Then came the invention of a new alloy that was 90% copper and 10% nickel. This was superior to steel and could handle far more pressure than a 100% copper line.

The copper-nickel brake line was:

• Rust and corrosion-resistant
• Flexible
• Easy to form
• Stronger than 100% copper
• Longer lasting
• Easier to damage when not handled right
• Kink-resistant

The cutting and bubble flaring of copper-nickel is easier than steel. Although you'll want to use a sharp tube cutter. This is one of the reasons copper-nickel is ideal as a brake line replacement.

Are Copper-Nickel Brake Lines Safe?

Sweden has conducted vehicle inspections since the mid-1960s. They tested how corrosion affected steel brake lines with various coatings. They also compared them to coatings on copper brake lines.

Regardless of the combination, the brake lines had 20% failure rates.
In the late 1970s, copper-nickel tests showed no corrosive impact for 12-years. This led to more studies to determine the ideal proportions of copper and nickel.

The first copper-nickel tubing included:

• 87.8% Copper
• 10% Nickel
• 1.4% Iron
• 0.8% Manganese

Each manufacturer has since altered the composition.

This initial copper-nickel brake line burst pressure was better than steel. Since then, copper-nickel materials are even stronger.

The refining process hasn't stopped. Science has reviewed everything that might impact the tubing. Studies included brake fluid viscosity, operating temperatures, tube length, and fluid flow rate.

All tests prove copper-nickel brake lines provide superior reliability to steel.

Are Copper-Nickel Brake Lines Legal?

Due to the terrible history, the use of copper brake lines became illegal. Since the release of the new copper-nickel solution, the product is legal to use.

The Copper Development Association is now opposed to copper brake pads. They are trying to reduce the amount of copper used in automobiles. This battle is not related to copper-nickel brake lines.

Brake Line Kits

To simplify the installation process, copper-nickel brake line kits are available. These self-contained kits are single-walled and come in 3/16” and 1/4" sizes. The materials are rust-proof and can handle both hot and cold temperatures.

Here are the burst pressures based on the line size:

• 3/16" is 11,909 PSI
• 1/4" is 8,932 PSI
• 5/16" is 7,146 PSI
• 3/8" is 5,955 PSI

The materials are 90% copper and 10% nickel.

Brake Line Replacement

Most vehicles come off the production floor with steel brake lines. The lines are difficult to access because they get placed on the frame early in the assembly process. The mass-production process means that the brake lines don't last long.

This is due in part to the cheapness of the parts. After all, the manufacturer wants to make a large profit. But this means owners living in the road salted north will need replacement parts sooner.

Attaching Brake Lines

Brake lines tend to snake around the entire car. The lines have to move between several systems. Here is one route the brake line travels:

• From the master cylinder down along the firewall
• Past the suspension
• To the anti-lock brake modulator
• Then to the proportioning valve
• To the rear wheels

The original brake lines are hard to get at. They are hard-baked into the frame. Getting to the lines means getting into the engine compartment.

Trying to replace the brake line with a steel part causes kinking problems due to the angle of the firewall. The steel brake line is not flexible enough to make the bend. This is where copper-nickel flexibility is the hero.

Zero Rust with Full Flexibility

Copper-nickel alloy does not rust. It is also flexible and bends by hand to work around obstacles, including firewalls.

Steel brake lines can bend in the right circumstances. But if the line needs reworking several times, the line becomes fractured. This makes it volatile to snap or kink.

Copper-nickel brake lines are always flexible. You can rework the lines many times without concern.

Fuel Tank Issues

One of the most difficult areas to work a replacement brake line is the fuel tank. The area has little room to maneuver and forces steel brake line users to remove the tank.

Copper-nickel brake lines are flexible enough to go over the top of the tank. You can push the line into position above the tank with little effort.

The one concern is making sure you tape the ends of the tubing off before pushing the line through. This will stop any dirt from getting into your brake lines.

Lifetime Warranty

Since the copper-nickel brake line never rusts or kinks, it's easy to apply a lifetime warranty. This alone is enough to consider the product. But its flexibility to get around crowded engine compartments is a bigger reason.

Copper-Nickel Brake Line Tubing Coil

The copper-nickel brake line tubing coil meets all SAE and ISO specifications. It is flexible, versatile, corrosion and rust-resistant, and comes with a lifetime warranty. The product is legal and exceeds stell specifications.

The product has longevity and can handle all high pressures used in braking. The metal composition protects the line from all weather conditions. It is also protected from winter salted streets.

dlq04

great news

Kyras

FINALLY!

Are there any you're interested in?

jukngene

Great news! Narrowed down your replacement choice?

cosmomiller

More on internal corrosion of brake systems.

Brake Fluid Testing: Bleeding and Flushing Minimizes Internal Corrosion in the Brake System

By Larry Carley




Brake fluid is something that should always be changed when the brakes are relined or when replacing a caliper, wheel cylinder, brake line, hose or master cylinder. But what about at other times? Should brake fluid be replaced for preventive maintenance? Most brake experts say yes!DOT 3 and DOT 4 brake fluid contains glycol ethers and other ethers, as well as various corrosion inhibitors and seal conditioners. When brake fluid is manufactured, it contains no moisture. But the fluid’s “hygroscopic” nature attracts water like a magnet. Open a bottle of brake fluid and let it sit overnight in a humid environment and the fluid will likely contain several percentage points of water by morning. That’s why you should never leave the container open (keep the lid tightly closed). That’s also why most fluid reservoirs on master cylinders are made of a translucent plastic so you can see the fluid level inside without having to open the cap.

Water contamination causes several things to happen. When the fluid absorbs water, it lowers the fluid’s boiling temperature. DOT 3 brake fluid, which has long been used in most domestic cars and light trucks, has a minimum dry boiling point of 401º F. A 3% level of water contamination will lower the boiling point 25% or 100º!

DOT 4 brake fluid, which is used in many European cars and performance cars, trucks and SUVs, has a higher dry boiling point of 446º F. DOT 4 soaks up moisture at a slower rate than DOT 3, but suffers a greater drop in heat resistance as moisture builds up. Only 2% moisture in DOT 4 fluid can lower its boiling point by almost 50% or 200º!

Actually, most OE and aftermarket brake fluids exceed these minimum DOT standards by a significant margin. Most DOT 3 “heavy-duty” fluids today have a dry boiling temperature of at least 475º F and some go as high as 550º F. By comparison, most DOT 4 “extra heavy-duty” fluids start out with a dry boiling temperature of 509º F or higher. Even so, moisture contamination still causes the boiling temperature to drop as the water builds up.

After only a year of service, DOT 3 fluid may contain as much as 2% water in some vehicles. After 18 months, the level of contamination can be as high as 3%. And after several years of service, it’s not unusual to find brake fluid that has soaked up as much as 7-8% water. The problem tends to be worse in older vehicles where there is greater seal wear and porosity in the brake hoses. We’ve seen vehicles that are six, seven or eight years old, and have had their brakes relined once or twice, and have never even had the brake fluid changed!

Under normal driving conditions, neglected brake fluid may not pose a serious safety concern. The calipers on most cars and trucks won’t get hot enough in everyday driving to make the fluid boil. But under severe conditions (as when driving down a mountain or towing a heavy trailer), the brakes may get hot enough to make the fluid boil. Once brake fluid turns to vapor, the bubbles cause an increase in the distance the pedal must travel to apply the brakes. This is called “pedal fade” and it may result in brake failure.

This condition should not be confused with “brake fade” that occurs when the brake linings get too hot as a result of prolonged braking. Brake fade requires greater and greater pedal effort to stop the vehicle as fluid boil increases pedal travel and makes the pedal feel soft or mushy. If the pedal goes all the way to the floor, the driver is in serious trouble!

The danger of fluid boil is greatest in front-wheel-drive cars, heavy SUVs and trucks because the front brakes run hotter than those in most rear-wheel-drive cars under the same operating conditions.

Semi-metallic linings and steel or aluminum caliper pistons compound the heat problem by conducting heat from the rotors to the fluid inside the calipers. So if the brakes are running hot, chances are the fluid is also getting dangerously hot.

Braking generates a lot of heat. A quick stop from 40 or 50 mph can raise the temperature of the front rotors a couple hundred degrees. Several hard, quick stops in rapid succession or riding the brakes while driving down a steep hill or mountain can increase rotor temperatures to 600° F or higher! We’ve heard stories about accidents where the driver stepped on the brakes only to have the pedal go straight to the floor. When the brakes were later inspected by the police (even minutes after the accident), the brake pedal felt normal because the fluid had cooled down enough to stop boiling. Scary!

RECOMMENDED FLUID CHANGES
Though the owner’s manuals for most vehicles have no specific time or mileage recommendations for replacing brake fluid, recommending a change every two years as preventive maintenance is a good way to minimize the danger of fluid boil and internal corrosion in the brake system.

You can’t tell how contaminated brake fluid is just by looking at it. New fluid may be clear to amber-colored or dyed brown. The fluid will typically become darker as it ages, but this doesn’t necessarily mean it’s contaminated. If you see rust or sediment in the fluid, the fluid is long overdue for a change.

One way to “see” how much moisture is in the fluid is to use a brake refractometer. This is a precision optical instrument that uses the fluid’s “refractive index” to reveal its condition. Moisture alters the way the fluid bends light, making it easy to “see” the amount of contamination on a scale in the eyepiece. To check the fluid, all you do is put a couple drops of fluid from the master cylinder on the instrument’s prism, lower the sample cover and look through the eyepiece. The refractometer scale will be calibrated for DOT 3 or DOT 4 fluids.

Another way to check the condition of the fluid is with a brake fluid tester. There are several types available. Some measure the fluid’s electrical resistance to give a “good” or “bad” indication. Others actually boil a small sample of fluid to calculate the fluid’s approximate boiling temperature (the results may vary a few degrees between tests due to the calibration limitations of the instrument). One such equipment manufacturer says DOT 3 fluid should be replaced if the boiling temperature is 312º F or less, or 340º F for DOT 4 fluid. If you don’t know what type of fluid is in the system (DOT 3 or 4), replace it if the boiling temperature tests less than 329º F.

Some say the best method for testing the fluid is to use special chemical test strips. There are two basic types, and both change color when dipped in the brake fluid. The color of the strip is then compared to a chart to determine the moisture content of the fluid or the chemical condition of the fluid.

One supplier of brake fluid chemical test strips says its product measures the “virtual age” of the fluid according to the level of amines or reserve alkalinity (which indicates how much corrosion inhibitor is left), the level of thermal oxidation that has occurred in the fluid and the presence of metal oxidation catalysts in the fluid.

The virtual age of the fluid has nothing to do with its actual age or the mileage on the vehicle. The brake fluid in a one-year-old SUV with only 15,000 miles on the odometer may have aged as much as the fluid in a three- or four-year-old car with 30,000 to 40,000 miles on the odometer if the SUV has been subjected to harsh operating conditions, such as extreme heat and/or extreme humidity.

High brake temperatures accelerate the rate at which the corrosion inhibitors in brake fluid break down. As the fluid ages, oxidation eats away at metal surfaces, creating dissolved acids and sludge that are carried with the fluid as it surges back and forth with every application of the brakes. The contaminants are abrasive and increase seal, piston and bore wear in the calipers, wheel cylinders and master cylinder. They can also attack and damage ABS solenoid valves and cause these valves to jam and stick.

The test strips that check the chemistry of the fluid typically reveal the presence of copper in the brake fluid. When the corrosion inhibitors break down, the copper brazing alloy inside the brake lines tends to leach into the fluid. Copper is not present in new brake fluid, and is the first metal that starts to dissolve when corrosion attacks the brake lines. As a rule, brake fluid should be replaced if the copper content exceeds 200 ppm (parts per million).

FLUSHING & BLEEDING
Though the fluid should be flushed when the brakes are relined or serviced, many shops skip this important step to save time or because they’re not convinced it’s necessary. Don’t make the same mistake. Many of these same shops have comebacks because of the old contaminated brake fluid that was left in the system.

Contaminated brake fluid contains rust and sediment, and offers no corrosion protection. Contaminants typically settle in the lowest part of the system, which are the calipers and wheel cylinders. Contaminants may also become trapped in the ABS modulator and valves. The result is often leaky seals and premature failure of newly installed components.

Flushing out all of the old fluid will not only remove moisture and solid contaminants, but also reduce or eliminate the need to bleed the individual brake circuits. You can use a power bleeder, vacuum siphon tool, an injector tool (that can do both pressure and vacuum bleeding and flushing) or even gravity bleeding to replace the old fluid. When using a vacuum bleeder, be sure to keep the master cylinder reservoir filled so air isn’t drawn into the system.

On some ABS-equipped vehicles, a scan tool may be required to cycle the ABS solenoids to remove trapped air from the ABS hydraulic modulator unit. Some modulators have special bleeder valves that can be opened to vent air. Others do not and require cycling of the solenoids to remove unwanted air.

Bleeding sequences vary depending on the application and technique. If you’re manually bleeding the brakes or using a vacuum bleeder, start with the brake farthest from the master cylinder. On front-wheel-drive vehicles where the brake circuits are paired diagonally, the right rear and left front circuits are typically bled first, followed by the left rear and right front circuits. Always refer to a service manual for the exact procedure, otherwise you may end up with air in a line and a soft brake pedal.

If you’re using a pressure bleeder, the recommended approach is to start at the master cylinder and work your way out to the farthest brake. If the master cylinder has a bleeder screw, do it first, then the ABS modulator (if equipped with bleeder screws), followed by each individual brake line.

Avoid the temptation to bleed only the brake line that was opened up to replace a caliper, wheel cylinder or hose. Air can migrate backward through the line and enter the master cylinder or other half of the brake circuit. It’s better to bleed all the brakes, than to risk a comeback because of a soft pedal.

When adding fluid to the system, use the type of brake fluid specified by the vehicle manufacturer (DOT 3 or 4). Brake fluid specifications can be found in the vehicle owner’s manual, maintenance guide, or on the master cylinder reservoir or filler cap.

Note: Be careful not to splash brake fluid on painted surfaces because it may damage the paint. Warning: If any fluid other than brake fluid is accidentally added to the master cylinder reservoir (such as motor oil, power steering fluid, ATF, etc.), it will contaminate the entire brake system and ruin the seals. If the contaminated fluid cannot be removed immediately from the master cylinder, you may have to replace all of the seals or hydraulic components in the entire brake system (OUCH!).