What is a brake line and when do you know replacing the brake line is already a need? The brake lines of a braking system play a very significant role in the brake function and performance of a car. You can only imagine the serious trouble you and your car will be in if brakes fail or are not performing properly.
The pressure coming from your foot on the brake pedal is transferred to the brakes through the brake lines. What most cars have are hydraulic braking systems. The brake fluid is stored in a master cylinder and transferred from this cylinder to the brake calipers through the brake lines whenever the brake pedal is activated. The slowing and then stopping of the car happens when the calipers clamp down on the brakes.
Hydraulic brake lines and hoses aren’t the first things most car owners think about when it comes to vehicle maintenance. Automakers also don’t list periodic replacement of them under routine services. But many factory-spec guides always state to inspect the condition of brake lines for any problem and advise accordingly.
Increasing need in replacing the brake line has become a norm nowadays as people are now keeping their cars longer and brake line pressures have become higher with the presence of ABS (Antilock Brake System) and stability control systems.
Replacing Brake Line: Causes of Brake Line Damage
- They degrade due to chemical reactions
Additive package preventing rust and controlling the pH of the fluid breaks down in the interior of the line. What follows is that it dissolves the copper brazing the inside of the brake line so it corrodes that part. Rust and de-icers on the other hand affect the exposed surfaces of the brake lines.
The chemistry of brines and other de-icing agents makes them so damaging. The MgCl2 (magnesium chloride) solution has high crystallization, high viscosity, potential, and strong hydrophilicity so it sticks on the surface of a metal and becomes a solution once more when exposed to a humid environment. This will eventually cause more severe corrosion than NaCl (rock salt), especially to parts with coarse surfaces.
All brake fluid absorbs water over time so it is important to flush the brake fluid on a regular basis. But if that isn’t done and as water builds up in the fluid it will cause rust and the metal brake lines start to corrode from within. You might not see the symptoms until the rust already caused a hole through the surface, by then you already have the risk of losing brake pressure.
As the brake line degrades from within the fluid-resistant inner lining may crack and the brake works its way to the outer layers of rubber. This will then cause a visible bulge in some cases.
A flexible rubber hose slowly starts to degrade from within due to heat and moisture in the brake fluid and worst cause the rubber to lose its structural strength in spots so eventually the line breaks apart.
- They degrade because of debris, UV exposure, and the like
With the issue of brake line corrosion automakers have given efforts to reduce it through galvanization, polymer coatings, and physical barriers. But what they can not control is prevent the pecking of road debris that causes corrosion.
The rubber hoses are exposed to the elements, and like any other rubber, products are subject to degradation because of UV rays, salt, road debris, and the like. The rubber can eventually fail if neglected and cause the loss of brake fluid. So all cars since the late 1960s already have dual brake systems, so in the event of a system failure, you still have at least two working brakes.
With this, late-model vehicles are now using stainless steel for the brake lines. But over time the stainless steel braided lines that don't collapse from the inside, can still become permanently dented or bent by flying road debris that might just bounce right off a rubber hose.
- They degrade because of age and environment
The life estimate of a typical ‘rubber' brake hose is 6 years, as said by BrakeQuip, A manufacturer of aftermarket rubber and high-performance stainless steel braided brake hoses. Age is a factor for brake line failure but the actual wear of the brake hoses that determines the time for replacing brake line still depends on weather conditions, like for example where you drive and store your vehicle and even your driving style, and the like.
Replacing Brake Line: Rubber Vs. Stainless Steel Braided Lines
As mentioned earlier, car manufacturers already came up with a number of innovations to reduce the wear and tear of brake lines. An example of this is coming up with steel braided lines. So what is the difference between a rubber brake line and a steel braided line?
Rubber Brake Lines
Most factory vehicles are made with rubber lines that have fluid-resistant inner liner surrounded by several thick layers of protective rubber. This makes it great for flexibility and easy routing through tight spaces. For decades, the rubber compounds prove themselves resilient in tough conditions and durable as well as time stretches on.
Protective metal or PVC sleeves are installed around rubber hoses for added protection when there’s a risk of direct contact with transmission components or hot engines.
Stainless Steel Braided Lines
Stainless steel brake lines, on the other hand, have a sealed inner hose typically made with flexible Teflon and surrounded by Kevlar and other protective layers added with a woven tapestry of braided steel strands for more strength.
So while these stainless steel braided lines cost more than rubber brake lines, they are much sturdier and offer a higher level of protection against other foreign debris found on roadways. They also swell a lot less than rubber ones do when brakes you apply your brakes and fluid pressure builds. And for that reason, changes in fluid pressure will reach the wheels faster and more efficiently. The driver will feel a more responsive brake pedal as a result. But the amount of actual fluid torque that will reach the wheels is not affected so braking strength will be the same for both rubber and stainless lines.
Replacing Brake Lines: Inspecting Brake Lines
To make sure everything is working as it should you must inspect the brake lines by feeling and by visually inspecting them.
Taking a feel of your brake lines include:
- Making sure they feel firm but flexible.
- Making sure it is neither hard and brittle nor soft and spongy.
- Have an assistant pump the brake pedal while you inspect the brake hoses and inspect the condition of your brake hoses under pressure. The expansion of the hose should be barely noticeable under pressure.
Visually inspect your brake hose conditions by checking for:
- Blister or bubbles on the hose while someone pumps the brake pedal so you can see it better.
- Chafe marks as a result of the brake hose rubbing against another component
- Cracks in the outer skin of the brake as you bend the hose
- Wet stains from where brake hose might have been starting to leak
- Bulging or expansion of the hose
- Some twist in your brake line – Department of Transportation (DOT) approved brakes have 2 lines of print on either side which will make it easier for you to tell if the hose is in fact twisted.
- Brake hose mounts that have become loose
Other symptoms to look out for when inspecting hose for wear and tear:
- You experience pulling on one side when braking which may be caused by one of your brake hoses being blocked.
- Spongy or low brake pedal that may tell you your brake hose is becoming old, soft, and weak, expanding under pressure. It also tells you there is a fluid leak and air has leaked into the brake system in place of the fluid that has leaked out. As the pockets of air bubbles are compressed and squeezed around by the moving brake fluid, you will feel a soft and mushy pedal
- You may experience dragging as you brake, which may have sprung from one or more restricted brake hoses.
- Intermittent issues with your brake may be caused by a hose that already has an internal fracture that created a one-way check valve effect.
- Brake system warning lights are on. It indicates that the sensors built into the brake pads detect that a minimum thickness point has already been reached, or that the brake fluid levels in the reservoir have already dropped below what is considered a safe point. This happens because a leak or a crack on the brake line causes the fluid level to drop noticeably.
Replacing Brake Line Cost
A brake line repair or replacement will cost you somewhere between $150 and $200. But if we are talking about parts only, it will cost only $30-$50, and the labor costs will be about $100-$150.
Replacing Brake Line: How long will it take?
A competent mechanic should be able to do all four brake lines in about 2 to 3 hours or even less. But if you’re going to try to replace it yourself, then the process could take anywhere from 3 to 8 hours, of course depending on your experience.
Take note that replacing a brake line also involves removing the wheels before being able to work on replacing brake line. If you’re doing it on your own and you’ve got the space, all the necessary tools and equipment plus of course a decent experience with automotive repair, then things are looking good and the process may just take anywhere between 3 to 5 hours.
But if you don’t have that automotive repair experience and lack the necessary tools and equipment, then expect the process of replacing brake line to take up to 8 hours, and even more. Take note that you will need ample space and to replace brake lines, you will need to elevate the vehicle, whether on ramps or jacks. So doing it yourself is not a simple DIY.
The length of time it will take to replace brake lines also depends on other factors like:
- the make and model of the car
- how many brake lines need replacing
- type of brake lines,
- Condition or how rusty the brake lines are
- The brake lines are metal
Brake lines are very important in the function of the brake system in your car. Any driver knows you need your brakes to be functioning well at all times to stay safe. A few factors like caustic chemicals in your brake fluid, debris, and aging components can cause it to fail. So it is important to watch out for any signs of trouble in your brake lines. You will be able to do this by carefully inspecting the brake lines visually, by feeling them, and by looking out for any common brake line problem symptoms.
And when you find out it’s time to replace the brake lines, it’s best to ask yourself if doing the replacement yourself or going to a reliable mechanic is the best way to go. You may choose to do it yourself but be mindful of the requirements you will need — not only your skills will be needed but also a handful of tools and equipment plus the workspace. Or you can have your brake lines replaced by a reliable and experienced mechanic so you can be fully confident that your brake lines are diagnosed and repaired properly. Not to mention you no longer have to worry about securing the needed tools and equipment.
Replacing brake line through a mechanic also tends to be a much speedier process than if you will do the work yourself. But either way, no need to worry too much as replacing brake line is relatively more affordable. It’s true that the cost may go up as much as up to the lower triple digits, but then when compared with other auto repair costs, it’s not too costly to replace your brake lines.