The brake lines are a crucial part of your braking system. But do you know how they work? While you were swapping out your brake pads or rotating your tires, you may have given your brake lines a cursory glance. Possibly you noticed that they weren’t the same length. Are you wondering if that’s normal?
Do brake lines have to be the same length? The length of your brake lines does not have an impact on braking power. Pressure in the hydraulic line will be equal despite the difference in length. What is on the front driver will inevitably be shorter than the front passenger or rear axle.
As you learn more about how your brakes work, you’ll realize that the brake lines are one of the strangest and most interesting parts of the whole system. We’re going to take a look at how the brake lines function and why length doesn’t matter, but pressure does.
How Do Brake Lines Work if They’re Not All the Same Length?
The most important thing to remember about the brakes is that it’s not the length of the brake line, it is the pressure of the brake fluid in the system.
- Pressure is applied through the master cylinder to compress the brake caliper or shoes in the brake drum in order to slow your car to a stop.
- In between the master cylinder and the wheels is a network of brake lines. They hold the brake fluid.
- Each brake line, regardless of length, is filled with brake fluid.
- All air is expunged. This means that when the reservoir adds fluid to the line to increase pressure, regardless of length, the same amount of pressure is applied to every wheel.
In summary, as long as the brake lines are adequately filled with fluid, the additional fluid forced into the lines from the reservoir will distribute equal pressure to each wheel, regardless of line length.
What is Brake Line Bleeding, and Why You Need to Know About It?
When you replace any major brake component (lines, calipers, junctions, etc.), you have to add fluid back to the system to maintain the equilibrium. There is a little screw that lets fluid out near the wheel.
What this does is allow the mechanic to remove all the air in the brake lines. This is, essentially, brake line bleeding.
The reason that bleeding the brake line is essential is that air in your lines causes a stutter in your braking power. Instead of a smooth constant pressure in the brake pedal, it will feel spongy. It will lead to a longer braking distance and lack of responsiveness, and therefore, a higher risk of an accident.
How Many Feet of Brakes Does a Car Have?
It all depends on the car, honestly. A two-ton, long-bed, crew-cab truck is going to have significantly more brake line footage than a European subcompact.
That truck may have well over 50 feet of brake lines, where that subcompact has something closer to 20 feet.
The distance between the master cylinder and the reservoir, and then the distance to each wheel from there, will determine the number of feet your car has in brake lines.
In some newer vehicles with more advanced braking systems, there may even be an electronic parking brake. This will use an auxiliary actuator to build and hold pressure in the brake lines when the parking brake is engaged.
In short, new cars may have even more brake line footage than you expect. Every car is completely unique, and there is no blanket standard for how many feet of brakes a car can have.
Why Aren’t the Brake Lines All the Same Size?
Funny enough, the brake lines are all different lengths, but they are also different diameters. The main line to the rear axle has to be thicker to distribute enough pressure for both back wheels to get equal braking power.
In other words, there’s enough fluid for two wheels in the one main line because it needs to be split between the two wheels. Therefore, the main brake line needs to be a larger diameter.
Then, in the front, the bulk of the braking system resides next to the steering column. It’s because of this that the brake line to the driver’s side wheel is shorter than that to the passenger side – that is, in most cases.
As previously mentioned, in newer vehicles with electric braking components, additional brake lines may go to any number of newfangled contraptions, including the anti-lock brake system. Depending on how complicated your braking system is, you could have a few extra feet of brake line!
What is the Difference Between a Brake Line and a Brake Hose?
Brake hoses are typically used at the hub to allow for articulation of the wheels to turn the vehicle. Some newer models have brake hoses that go into those odd auxiliary actuator features that make up the electrical components. The hoses are made of a flexible, reinforced rubber tubing.
As mentioned, brake lines deliver the pressure needed for the calipers to clamp and the drum shoes to engage. They are made of steel piping.
Essentially, the hose adds flexibility at the wheel so that the hard brake lines don’t take too much motion. Too much outside pressure on the stainless steel brake line wears on the material and eventually leads to brake failure. The hose works to alleviate that outside pressure.
How Often Should You Replace Your Brake Lines?
Brake lines are supposed to survive the lifespan of the vehicle. This is entirely dependent on where you live, though, as well as how well you take care of your car. For example, northern states where harsh winters come with salt on the roads are particularly hard on metal components. This includes your brake lines.
In desert climates, the hoses are more prone to dry rot because of the lack of humidity (and the nature of rubber tubing). However, the brake lines tend to last longer in a desert climate because they are less likely to rust.
Junctions and mounting points are more likely to rust and fail before your brake line does. However, rust is contagious, and it will spread to your brake lines next.
Basically, though, your brake lines should not be replaced with any frequency. Keep your car clean and watch out for any risk of rust to preempt brake line failure. With care and attention, the lines may never need to be replaced.
Just a Quick Note About Brake Fluid Before You Go
Your brake lines only work as long as there is adequate fluid in the lines. Unless you’ve just recently had some kind of maintenance, the level of brake fluid should not change.
You should not be burning through brake fluid. If the level in the reservoir is low, you have a leak. This may not mean an issue with the lines, though. More than likely, you’ll need to replace your brake pads because you’ve let them wear too thin.
If that does not fix the issue, check the bleeder valves and the reservoir for cracks. Time spent in a hot environment can lead to the plastic cracking. Beyond this, you may have issues with your brake lines, so you should get a mechanic to check it out.
Wrapping It Up
The brake lines in any car are going to vary not only in length from wheel to wheel but also in diameter from front to back. The length of the brake lines does not affect braking power. This is because the hydraulic pressure continues to be equal as long as the fluid levels are adequate and there is no air in the line.
