Earl's Performance® 610004ERL - Speed-Flex™ Brake Hose

With the larger and heavier cars, like Ford’s GT-40s, enough of the available brake pedal travel was used up in expanding the flexible brake hoses so that there was insufficient pedal travel left for safe braking. In the mid-1960s, Earl’s pioneered the use of armored flex hose of extruded PTFE to solve this problem. The stiffness of the PTFE liner combined with the tightly woven high tensile stainless steel outer braid solved the pedal travel problem. By eliminating the line swell it also dramatically increased the firmness and feel of the brake pedal which allowed the drivers to modulate the brakes more efficiently. Improved abrasion resistance and increased temperature capacity are secondary advantages. Since brake actuation produces high pressure with very little fluid displacement, we recommend -2 & -3 SPEED-FLEX™ for brake systems. Clutch actuation, on the other hand, requires moderate pressure but considerable displacement of fluid. For hydraulic clutch systems we recommend the use of -4 SPEED-FLEX™.

In recent years various fuel manufacturers have added any number of new unpublished additives to their blends rendering some of them incompatible with synthetic rubber lined hose. Earl’s Speed-Flex™ PTFE lined stainless braided hose is impervious to any automotive fuel blend known to us and may be the best choice for use with modern racing gasolines. All SPEED-FLEX™ hoses are compatible with gasoline, hydrocarbon fuels, alcohols, nitro-methane, mineral and synthetic lubricants, and high density fuel additives. Size 6 and 8 are carbon lined to dissipate static electricity. Some caution is necessary in the selection of armored PTFE hose. The PTFE liner is manufactured in two wall thicknesses, commercial (.03") and aircraft specification (.040"), Earl’s uses the thicker and stronger wall. There are also hoses in the marketplace manufactured in such a manner that the stainless braid is loose on the PTFE liner. These hoses offer good pressure capacity but limited expansion resistance. Earl’s SpEED-flEx™ hose is the standard of the industry.