1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Release No. Released 2008 10 29 N-STATUS Replaced by WSS-M99P26-A2 A. Wedepohl, FNA 1994 11 22 NC00E10244447047Revised 3.3.1 & 3.4.1 A. Yuhas 1989 10 06 Released K.P. Minnich WP 3948-a Page 1 of 5 HYDRAULIC BRAKE HOSE ASSEMB
2、LY, PERFORMANCE ESA-M99P26-A NOT TO BE USED FOR NEW DESIGN 1. SCOPE This specification defines the performance requirements of hose fabricated with an extruded tetraflouroethylene inner tube reinforced with a stainless steel wire braid covering, assembled with steel or brass end fittings. 2. APPLICA
3、TION This specification was released originally for hydraulic brake hose assemblies to be used in place of traditional hard-line brake tubes, in underhood applications. These hose assemblies provide superior heat and fluid resistance than conventional rubber jacketed hydraulic brake hose. NOTE: This
4、 hose construction is not intended for applications requiring repeated flexing. 3. REQUIREMENTS 3.1 STATISTICAL PROCESS Suppliers must conform to the requirements of Ford Quality System Standard Q-101. A mutually acceptable Control Plan as described therein is required for material/source approval.
5、Appropriate statistical tools must be used to analyze process/product data so that variation in the final product is continuously reduced. 3.2 INFRARED SPECTROPHOTOMETRY AND/OR THERMAL ANALYSIS Ford Motor Company, at its option, may conduct infrared and/or thermal analysis of material/parts supplied
6、 to this specification. The IR spectra and thermograms established for initial approval shall constitute the reference standard and shall be kept on file at the designated material laboratory. All samples shall produce IR spectra and thermograms that correspond to the reference standard when tested
7、under the same conditions. 3.3 HOSE CONSTRUCTION The hose shall consist of an inner tube of virgin polytetrafluourethylene (PTFE) reinforced with a stainless steel wire braid covering. ENGINEERING MATERIAL SPECIFICATION ESA-M99P26-A WP 3948-b Page 2 of 5 3.3.1 Inner Tube The inner tube shall be a sm
8、ooth-bore seamless tube of polytetrafluoroethylene. The tube material shall conform to the requirements of virgin Type III, Grade 2, Class B resin per ASTM D 1457, except that a maximum of 2 % by weight of additives is permissible. Size of Inner Tube ID, mm 6.35 +/- 0.58 4.75 +/- 0.58 Wall Thickness
9、, mm 0.76 +/- 0.13 0.76 +/- 0.13 3.3.2 Wire Braid Reinforcement The reinforcement shall consist of 0.20 mm to 0.40 mm diameter SAE Type 302 or type 304 stainless steel wire applied with a weaving construction of two over and two under such that a minimum 90 % coverage is achieved. 3.3.3 Coupling Con
10、struction The coupling shall be designed, inserted and crimped so that no internal hose abrasions, cuts or flaws shall result. Sharp corners shall be avoided where the coupling contacts the hose to prevent cutting of the hose when subjected to internal pressure. The material must conform to all the
11、requirements of FMVSS 106 brake hoses and the following requirements. 3.4 INITIAL QUALIFICATION These tests are to be conducted by all material suppliers prior to source approval and at least once every 6 months. 3.4.1 Constriction The constriction shall be measured by dropping a gage plug a distanc
12、e of 76 mm through the inside diameter of the brake hose. The hose is to be held vertically and the gage plug must drop the required distance within a maximum time of 5 seconds. Both ends of the hose assembly must be checked. When the hose in one fitting is blind or at an angle to the centerline of
13、the hose, it is permissible to check entire hose length from one end. The gaging portion of the plug shall be 11.4 to 14.0 mm long. The leading edge of the plug shall have a corner radius of 0.64/0.89 mm. The total weight of the gage shall be 57 +/- 3 g. ENGINEERING MATERIAL SPECIFICATION ESA-M99P26
14、-A WP 3948-b Page 3 of 5 The gaging plug diameter will be: ID of Tube, mm Gaging Plug Diameter, mm 6.75 3.95 + 0.01 4.75 2.58 + 0.01 3.4.2 Expansion and Burst Strength All 6.35 +/- 0.58 mm I.D. brake hoses must have a maximum expansion rate of 0.72 cm3/m at 6.9 MPa and 1.08 cm3/m at 10.3 MPa. Test M
15、ethod: FMVSS 106, Section S6.1. 30 min after the expansion test, the hose assembly shall be burst tested. When tested under hydraulic pressure, each sample hose assembly must withstand a maintained pressure of 41.4 +/- 0.7 MPa for 2 minutes. The pressure shall then be increased at the rate of 172 +/
16、- 69 MPa/minute until burst occurs. The minimum burst pressure is to be 62 MPa. No seepage is permitted during the 2 minute hold period. 3.4.3 Tensile Strength, min (FMVSS 106, Section S6.4) 24 h after crimping 1.76 kN Within 12 h after crimping 1.54 kN All hose assemblies must withstand a minimum t
17、ensile load without separation of the hose from its end fittings. 3.4.4 Water Absorption The hose assemblies must pass all burst and tensile tests after a 72 h soak in water. 3.4.4.1 Burst Test per para 3.4.2 within 10 min of removal from water soak. 3.4.4.2 Tensile Strangth Test per para 3.4.3 with
18、in 30 minutes of removal from water soak. 3.4.5 Low Temperature Flexibility After cold soaking 2 assemblies at - 54 to - 57 C for 72 h, they shall be bent around a 76 mm diameter mandrel within 5 seconds. Care must be taken during the bending so that no part of the hose assembly has less than an equ
19、ivalent of 76 mm diameter bend. Remove reinforcing cover and inspect innner tube for cracking or breaking. ENGINEERING MATERIAL SPECIFICATION ESA-M99P26-A WP 3948-b Page 4 of 5 3.4.6 Brake Fluid Compatibility, Constriction, and Burst Strength The hose assemblies shall meet the constriction (para 3.4
20、.1) and burst (para 3.4.2) requirements after having been subjected to a temperature of 93 C for 70 h while filled with SAE RM66-04 compatibility brake fluid per FMVSS 106, S6.7. 3.4.7 Heat Aging and Cold Bend Resistance After 10 days of heat aging at 120 +/- 3 C, followed by a cold soak at - 46 to
21、- 48 C, bend the brake hose around a 76 mm diameter mandrel. Remove the reinforcing cover and inspect inner tube, no cracks are allowed. Test Method: Heat age at 120 +/- 3 C (ASTM D 573) for 10 days (240 h). Remove from the oven and allow to stabilize to room temperature for 6 - 12 h. Condition hose
22、s and a 76 mm diameter mandrel for 48 h in a cold chamber maintained at - 46 to - 48 C. Without removing from chamber, bend the hose 180 deg around the mandrel within 5 seconds. Remove the hose from the cold chamber and allow to stabilize to room temperature for 1 - 6 h. Remove the reinforcing cover
23、, wrap around a 76 mm diameter mandrel and inspect, without magnification, for cracks. A crack is defined as a discontinuity in the inner tube. 3.4.8 End Fitting Corrosion Resistance (FMVSS 106, Section S6.9) After 24 h of exposure to salt spray, a hydraulic brake hose end fitting shall show no base
24、 metal corrosion on the end fitting surface. 3.4.9 Impulse, min 150 cycles The hose assemblies must show no sign of fluid seepage, cracking or separation when impulse tested under hydraulic pressure. The assemblies must withstand a maintained pressure of 13.8 +/- 0.07 MPa for 2 minutes and a minimum
25、 burst pressure of 34.5 MPa. pressure of 34.5 MPa. Test Method: The hose assemblies are to be cycled a minimum of 150 times with the fluid and ambient temperature of 146 +/- 3 C. A cycle consists of 1 minute at 11.0 MPa and 1 min at 0 MPa. The current production Ford Motor Company hydraulic brake fl
26、uid will be the pressure medium. After the impulse test, the hose assemblies shall be conditioned at ambient temperature for 45 minutes minimum and be burst tested (reference para 3.4.2) 3.5 ACCEPTANCE (IN-PROCESS) TESTING The tests and frequencies shall be specified in the applicable Engineering Sp
27、ecification noted on the engineering drawing. Tests must be completed with production parts on a continuing basis. ENGINEERING MATERIAL SPECIFICATION ESA-M99P26-A WP 3948-b Page 5 of 5 3.6 SUPPLIERS RESPONSIBILITY All materials supplied to this specification must be equivalent in all characteristics
28、 to the material upon which approval was originally granted. Prior to making any change in the properties, composition, construction, color, processing or labeling of the material originally approved under this specification, whether or not such changes affect the materials ability to meet the speci
29、fication requirements, the Supplier shall notify Purchasing, Toxicology and the affected Materials Engineering activity of the proposed changes and obtain the written approval of the Materials Engineering activity. Test data, test samples and a new code identification are to be submitted with the re
30、quest. Substance restrictions imposed by law, regulations or Ford, apply to the materials addressed by this document. The restrictions are defined in Engineering Materials Specification WSS-M99P9999-A1. 4. APPROVAL OF MATERIALS Materials defined by this specification must have prior approval by the
31、responsible Materials Engineering activity. Suppliers desiring approval of their materials shall first obtain an expression of interest from the affected Purchasing, Design and Materials Engineering activity. Upon request, the Supplier shall submit to the affected Materials Engineering activity a co
32、mpleted copy of their laboratory test reports, signed by a qualified and authorized representative of the test facility, demonstrating full compliance with all the requirements of this specification (test results, not nominal values), the material designation and code number, and test specimens for Ford evaluation. Fords engineering approval of a material will be based on its performance to this specification and on an assessment of suitability for intended processes and/or applications. Upon approval, the material will be added to the Engineering Material Approved Source List.
