What’s Stopping You:
Rubber vs Braided Stainless Steel Brake Hoses Explained
Figure 1:An unfortunate reminder of how important a healthy brake system is
What’s the most overlooked vehicle component that is part of a bigger system that is routinely take for granted, is vital to protecting our vehicle from damage and is relied on repeatedly every time you drive your car? Hint: It lives, hidden behind your wheels and is subject to dirt, heat and extreme pressure.
The answer is the brake flex hose that is found and every car or truck, new or old. Why should you care about this short section of OEM rubber brake line and what does it have to do with the performance and safety of your brakes?
The answer is plenty but first we need to better understand a couple things about the hydraulic brake system found on everything from a 1969 Camaro to at 2020 Chevrolet Pickup truck.
Figure 2: Brake pressure gauge used to measure brake fluid pressure
The brake system on your car or truck is a hydraulic system in that it uses a combination of fluid and pressure to activate the pistons in a brake caliper or wheel cylinder which then push or clamp a brake pad on a rotating rotor or brake drum. It might surprise you to learn that most brake system require a minimum of 1200 psi of pressure to work as designed. Some performance applications can reach 1800psi requirements.
Figure 3: Extreme example of suspension travel the flex hose must compensate for
All vehicles, new or old, stock or modified must have a flexible connection between a vehicles hard (steel) brake lines that are mounted along the chassis and the brake calipers or brake drum mounted at the wheel to take account for the up and down range of motion that the suspension has it reacts to bumps in the road.
The flex lines that came originally on 1960’s and 70’s muscle cars were made out made out of reinforced EPDM rubber that is layered with a nylon weave for strength. Rubber flex lines fit OEM vehicle manufacturers requirements for fit, durability, low maintenance, function and cost.
The downside to rubber flex hoses is that they swell or have some give when brake pressure is applied and harden with age. Brake line swell robs and delays the brake pressure supplied by the master cylinder on its way to the calipers and ultimately the activation of the brake pads or shoes.
Even if you were OK with less brake pedal sensitivity, the bigger safety concern is the hardening of the rubber that makes up the brake line or contaminant build up inside the line. As flex lines harden. Which can happen in as little as 15 years from their service date, they can crack or catastrophically fail which would lead to the complete loss of brake pressure, brake fluid volume and the ability to stop your vehicle.
Figure 4: The Right Stuff's DOT compliant braided flex hose
Born out of racing, Braided Steel Brake lines that are DOT approved are a simple but effective way to increase your vehicles sensitivity to braking inputs and provide a durability in extreme conditions (off-road, track days) that rubber flex lines could never afford.
Figure 5: Nova with upgraded braided flex brake line
Upgrading your existing brake system or adding them to a disc brake conversion kit will increase brake pedal sensitivity in that it decreases the amount of time it takes to apply critical brake pressure to the calipers or drums to their maximum level. It’s important to understand that this upgrade will not increase the total pressure that your brake system can generate but it does ensure that the pressure and volume delivered by upgraded booster/master cylinders are transmitted to brake calipers is efficient and effective.
First Place Auto Parts offers both braided steel and restoration quality rubber brake flex lines depending on what you plan to do with your vehicles. The next time you have your wheels off, take a look at your brake lines and see if they have hardened, have cracking present or are weeping brake fluid. Whether is for safety or performance, consider a set of flex lines from First Place Auto Parts. Replacement is easy to do, provides a performance increase in braking that can be felt and provides peace of mind for this often-overlooked brake part.