ATE brake hose assemblies Highest mechanical stability under load, highest compressive strength and resistance 1
ATE brake hose assemblies History Hydraulically actuated brakes, and consequently brake hose assemblies, too, similar to today's designs, have been available from Alfred Teves (ATE) since the 1920s. The first production car with a hydraulic brake from ATE was the 1927 ADLER Standard 6 and Favorit. This vehicle already featured brake hose assemblies on the front and rear axles. The demands on the "connecting hose" in the Adler were similar to those raised today, aside from the temperature level and certain other things. Owing to the growing demands, e.g., high temperatures, the testing of brake hose assemblies has acquired considerable scope. 2
Brake hose assemblies Definition Brake hose assemblies are used at the transitions to parts which are subject to heavy dynamic stresses steering knuckles or brake calipers, for instance. They ensure the proper transfer of brake fluid pressure to the brakes even under extreme conditions. Along with mechanical durability and pressure resistance, chemical resistance, e.g., to oil, fuels and other environmental influences, as well as good thermal resistance are essential requirements. To the high demands made on the system of brake lines, new ones have been added by ESP or TCS. The brake hose assembly plays an important role as damper and solves the problems raised by cramped installation positions. 3
Influences on brake hose assemblies All weather factors Operating pressure > 120 bar and brief peak overpressure of 160 bar (max. about 10 min.) Flying stones Mechanical stresses caused, e.g., by improper laying of the brake hose Damage like chafing Other influences Road salt Temperature loads caused by drier or heat radiator temperatures > 100 C during refinishing of a vehicle 4
Effects of defective brake hose assemblies Cracks owing to excessive mechanical stress or environmental influences If cracks are visible in the outer rubber layer of the brake hose, the car will fail to pass the next official inspection. In the initial stage (shortly after their formation) cracks have no negative influence on the operation of the brake hose, however. But if the cracks in the outer rubber layer go undiscovered over a lengthy period, environmental influences (e.g., moisture, cleaning agents or lubricants) may damage the pressure-resisting braiding beneath the rubber layer, and that can substantially impair proper functioning. The garage will have to examine the brake hoses carefully and replace them if necessary. 5
Present-day demands on efficient brake hoses Use over a large temperature range must be possible Low volumetric expansion of brake fluid High flexibility in the cold Negligible moisture absorption by inner and outer rubber layers High chemical resistance to the additives in high-grade brake fluids Great resistance to weathering and ozone These demands too go to define the characteristics of our ATE brake hose assemblies. 6
Design of ATE brake hose assemblies Outer rubber layer Double braiding Inner rubber layer The brake hose assembly structure features an inner tube, double-layer braiding as pressure resistor, and an outer rubber layer to protect the pressure-resisting braiding from external influences. Normally, at both ends of the hose threaded fittings are attached for making the connections with the brake pipe and caliper. But it is also possible to permanently connect the brake pipe with the brake hose assembly by means of a special connector (and to save effort for installation in the vehicle this way). 7
ATE brake hose assemblies - Types Mold-heated brake hose (vulcanized in a mold) TYPE 6/7 Freely heated brake hose (vulcanized in a water vapor atmosphere) TYPE 9 CR/EPDM EPDM RAYON PVA RAYON PVA CR/EPDM EPDM Rubber material CR EPDM = Chloroprene Rubber = Ethylene-propylene-diene copolymer Braiding Rayon PVA = Kunstseide = Polyvinyl alcohol 8
ATE brake hoses Characteristics of Type 9 Improved properties of material and product Vulcanized in a water vapor atmosphere Improved EPDM EPDM Double braided layer of PVAL yarn Service temperature range: -40 C to +120 C, briefly +160 C (max. about 10 min.) Very little elasticity under compressive stress, for well-modulated brake application EPDM PVAL PVAL Outstanding resistance to dynamic loading -40 C to +120 C, briefly +160 C (max. about 10 min.) Very good resistance to ozone Minimal volumetric expansion under pressure and minimal water absorption 9
Advantages & properties of ATE brake hose assemblies Branded product ATE utilizes the technology of OEM Continental. Use of the most up-to-date technology Mostly extruded connectors used, more than 70 braiding machines for producing the braid, autoclaves or vulcanizing presses and automatic surface control for the production of the inner and outer rubber layers Quality & safety guaranteed Test stands and laboratories are amply available for testing to customer specifications. Extraordinary quality standard owing to certification ATE brake hose assemblies comply with FMVSS106, and production is certified to ISO 14001. In addition, with the in-house ATE N standard they exceed the legal requirements. Hose marking The DOT symbol (DOT = US Department of Transportation) confirms the agreement of the hose with the most common motor vehicle safety regulations. High level of quality Continental uses only high-grade, long-lived materials to manufacture the brake hose assemblies. The surface protection of the connectors of the ATE brake hose assemblies is free of Cr-6, complying with the EU end-of-life-vehicle directive. 10
ATE brake hose assemblies Fittings / extras To the high demands made on the system of brake lines, new ones have been added by ESP or TCS. The brake hose assembly plays an important role as damper and solves the problems raised by cramped installation positions. To simplify fitting, preassembled brake hose assemblies are used to reduce the number of unchecked screwing operations and enabled simplified fastening in the vehicle. ATE brake hose assemblies are available in OE quality together with fittings of, e.g., the following types: Internal thread External thread Spacer Protective spring Floating attachment by means of clip-in rubber fasteners 11
ATE brake hose assemblies Notes on installation Fit brake hose assemblies in exact sizes and do not twist. Do not bend too short to fit. It's better to use an additional banjo union with banjo bolt. Lay brake hose assemblies so that chafing is impossible. Where there is danger of contact, make the brake hose assembly safe with a protective hose or by means of an additional hose clamp and tension spring. Should a brake hose assembly additionally be provided with a protective hose, this hose must neither be displaced nor removed. Do not lay near the exhaust system. Brake hose assemblies also must not come near the exhaust system when the vehicle springs deflect or the wheels are turned. If necessary, fit additional heat insulation. Do not lay in the immediate vicinity of lubrication points so as to avoid contact with excess oil or grease. Further details are contained in the instructions for use included with every ATE brake hose assembly! 12