Get The Sponge Out

July 2017
By Jim Smart

Classic Tube takes the “sponge” out of your brake pedal with high-performance braided stainless steel brake hoses. When you combine StopFlex brake hoses with preformed lines and hardware from Classic Tube, you’re get¬ting outstanding “Made in USA” quality to install on your classic Mustang.

UNLESS YOU’RE PERFORMING A CONCOURS RESTORATION ON YOUR 1965-1978 MUSTANG, you will want to perform constructive modifications that make a vintage car safer and more enjoyable to drive. This approach to classic Mustangs—known as restomod—is the fine art of taking a popular American classic and improving it. You end up with great classic looks with modern performance to match.

One core issue with these older Mustangs has always been brake function and making it better. Classic Tube was the first at bat with preformed galvanized and stainless steel brake lines and flexible reinforced hoses for vintage Mustangs. Classic Tube has hit another homerun with StopFlex stainless reinforced brake hoses for older Mustangs. The company’s StopFlex brake hoses are extremely durable braided and wrapped stainless, and as a result, they are minimally flexible to give your braking system a firm pedal. What’s more, they are DOT Compliant for street use; have minimal volumetric expansion (firmer pedal); immediate response; not as soft as with other hoses; and corrosion resistant.

What makes these hoses superior to your Mustang’s original equipment is their construction. StopFlex brake hoses incorporate a special three-layer design for superior strength and virtually no expansion. According to Classic Tube’s Paul Fix, StopFlex begins with a tough Teflon PTFE core liner, then a stainless steel braid, and finally, a clear vinyl cover that will outlast any conventional brake hose. Conventional rubber brake hoses deliver a spongy brake pedal because these guys flex under hard braking. That is approximately 1,200psi when you romp on the brakes per Classic Tube. And because StopFlex has a strong core and stainless steel braided construction, you get a hard brake pedal and a crisp response.

When you combine StopFlex brake hoses with preformed lines and hardware from Classic Tube, you’re getting outstanding “Made in USA” quality to install on your classic Mustang.

01. StopFlex stainless braided brake hoses provide a firmer brake pedal feel, look sharp, and will last virtually the life of your Mustang.

02. Check out these Stop Flex stainless braided and laminated brake hoses from Classic Tube. The company has its roots in classic Mustangs and vintage road racing.

03. This is a Ford Granada-style single-piston front disc brake fitting with two copper compression washers, which is typical of Mustang disc brakes from 1968-1978. Earlier 1965-1967 four-piston calipers have a straight-in brake hose connection sporting a single copper compression washer. The brake hose banjo bolt is removed from the caliper using a 9⁄16-inch box-end wrench. Be sure to use a catch pan or bleeder hose to capture brake fluid. If it has been a while since you’ve flushed and bled the brake hydraulic system, flush the system at this time. Brake hydraulic systems should be flushed and bled every two years when you perform engine cooling system services.

04. Disconnect the brake hardline using a 3/8-inch line wrench. Then remove the hose bracket with a 1⁄2inch socket. Take extra care not to get brake fluid on paint or undercoat. It will permanently damage it.

05. Install the two copper washers included in the StopFlex kit on both sides of the hose-to-caliper fitting. These are known as crush, or compression, washers because that’s exactly what they do. Never use anything but copper washers here, and always install new ones. Copper washers conform (crush) to the concentric rings in the caliper and brake hose banjo fitting, providing a proper seal and containment of brake hydraulic pressure.


06. Tighten the brake-fitting banjo bolt to where you feel the washer crush and the bolt is seated firmly. At this point, other than bleeding the system, you’re done with the front brake hose installation.

07. Rear brake hose replacement is straightforward with two steel brake lines and the rear axle vent fitting. Disconnect the lines first using a 3/8-inch line wrench, and remove the vent fitting using a 9/16-inch open-end wrench.

08. The brake hose is tied to the body at this bracket. Disconnect the hard line using a 3/8-inch line wrench, also called a tubing wrench.

09. Install the Classic Tube Stop Flex rear brake hose at this body bracket, as shown, using the provided retaining clip. This clip can be challenging, so be patient.

10. The rear brake hose installation at the body bracket is complete. When you tighten brake line fittings, tighten, and then loosen. When you tighten the fitting again, go even tighter to seat the flared fitting. This reduces the chances of leakage.

11. Install the Classic Tube Stop Flex hose at the rear axle, as shown, with the vent tube fitting first, then start the brake line fittings. Once the fittings are started, you’re free to seat the vent tube fitting and tighten lines. As with the body-mounted line, seat the lines, loosen, and retighten firmly. This approach seats the flare. The completed rear axle Stop Flex hose installation looks good and will last the life of your Mustang.

12. The rear axle vent hose is connected like this. You may use a spring clamp, which makes for a clean installation, or install a worm gear clamp. Using fuel injection hose clamps also gives your installation a professional look.

13. The rear axle vent hose joins the body here and the end of the hose is inserted into the central framerail. We used an Adel clamp here.

14. Four-piston brake calipers, such as we see on 1965-1967 Mustangs (and some of the aftermarket stock replacement disc brakes), have this single copper compression washer, instead of two from 1968-up.

15. When you install StopFlex hoses fore and aft, it is suggested you flush the brake hydraulic system. We’re bench bleeding the master cylinder as installed in the vehicle. All you have to do is add fluid to each reservoir and slowly depress the brake pedal until all the air is purged. Protect your Mustang’s paint finish inside and out. Mineral-based DOT 3 brake fluid will damage paint. Even the tiniest droplet will lift paint, so cover all the painted surfaces when you add fluid.