1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions Ver. 1 2008 11 12 Activated A. Wedepohl, FNA Printed copies are uncontrolled Copyright 2008, Ford Global Technologies, LLC Page 1 of 4 HOSE, HYDRAULIC BRAKE WITH 304 STAINLESS WSS-M99P26-A2 STEEL OVERBRAID HOSE, HYDRAULIC BRAKE WITH 316 STAINL
2、ESS WSS-M99P26-A3 STEEL OVERBRAID 1. SCOPE These specifications define the performance for a brake hose with an extruded polytetrafluoroethylene inner tube reinforced with a stainless steel wire braid covering and assembled with stainless steel hose collars. 2. APPLICATION These specifications were
3、released originally for hydraulic brake hose where flexibility was needed in the engine compartment for assembly, serviceability or small degrees of relative motion. This hose construction is not intended for repeated flexing as experienced in jounce hose applications. The free length of the hose sh
4、ould be less than 203 millimeters (8 inches). This construction offers better heat resistance than a typical reinforced rubber hose. At the time this specification was released, the common hose sizes were: Nominal ID Nominal OD 4.76 mm (3/16 inch) 7.9 mm 6.35 mm (1/4 inch) 9.3 mm 8.0 mm (5/16 inch)
5、11.0 mm 3. REQUIREMENTS The requirements listed in this specification are for validation of the hose construction and crimp design. These requirements are usually tested at the design verification (DV) level. Sample sizes required to fulfill each requirement are listed in SAE J1401 unless otherwise
6、noted. In some cases, more samples may be required. Brake hose must conform to all requirements of the Federal Motor Vehicle Safety Standard MVSS 106 and the following requirements. In process testing for production hose assemblies should be conducted according to the test frequencies and appropriat
7、e sample sizes as defined by the engineering specification listed on the print. 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). 3.2 HOSE CONSTRUCTION 3.2.1 The hose
8、shall consist of an extruded polytetrafluoroethylene (PTFE) inner tube that meets the requirements of ASTM D4895 Type 1, Grade 4, Class B. 3.2.2 A2: The reinforcing wire braid and hose crimp shall be UNS S30400. A3: The reinforcing wire braid shall be UNS S31600 and S30400 for the hose crimp. ENGINE
9、ERING MATERIAL SPECIFICATIONWSS-M99P26-A2/A3 Printed copies are uncontrolled Copyright 2008, Ford Global Technologies, LLC Page 2 of 4 3.3 CONSTRICTION not less than 64% (SAE J1401 or FMVSS 106) of the inside diameter. 3.4 VOLUMETRIC EXPANSION, max (SAE J1401) Hoses must have a volumetric expansion
10、below the listed maximum for each pressure. Maximum Expansion, cc/meter Hydraulic Brake hose ID Test Pressure 6.9 MPa 10.3 MPa 20 MPa 4.76 mm (3/16“) 0.590 0.787 1.575 6.35 mm (1/4“) 0.72 1.08 1.85 8.0 mm (5/16“) 1.50 1.90 3.0 3.5 BURST STRENGTH, min 62 MPa (9000psi) (SAE J1401) Test hose assemblies
11、 at the minimum and maximum of the compression range for hose crimp diameter. Test burst strength per SAE J1401, except the hose assemblies must withstand a maintained pressure of 41.4 +/- 0.7 MPa (6000 +/-101 psi ) for 2 min. The pressure shall then be increased at the rate of 172.5 +/- 69 MPa /min
12、 (25,000 +/-10,000 psi) until burst occurs. No leakage is permitted during the 2 minute hold period. 3.6 BRAKE FLUID COMPATIBILITY (SAE J1401) Hose assemblies at the minimum and maximum of the compression range for hose crimp diameter must meet the requirements of this specification for Constriction
13、 and Burst Strength after exposure to the brake fluid. 3.7 WHIP RESISTANCE, min. 70 hours (SAE J 1401) No Leakage Not required when the free length of the production hose is less than 203 mm. Use hoses with a 300 mm free length if testing is required. Standard length allows comparisons with other ho
14、se constructions or crimp designs. 3.8 TENSILE STRENGTH, min (SAE J1401) Test hose assemblies at the minimum and maximum of the compression range for hose crimp diameter. Slow Pull, 25.4 mm/min 1761 N (396 lbf) Fast Pull, 50.8 mm/min 1975 N (444 lbf) ENGINEERING MATERIAL SPECIFICATIONWSS-M99P26-A2/A
15、3 Printed copies are uncontrolled Copyright 2008, Ford Global Technologies, LLC Page 3 of 4 3.9 COLD BEND No cracking (SAE J1401) or breaking Perform the test as specified except cold soak at least two hose assemblies between -54 to -57 C. Remove the stainless steel braid to inspect the inner tube.
16、3.10 OZONE RESISTANCE (SAE J1401) Static: No visible cracks when viewed under 7X magnification after exposure. Dynamic: No visible cracks after 48 hours. 3.11 END FITTING CORROSION RESISTANCE (Salt Spray, SAE J1401) No base metal corrosion on the end fitting surfaces. 3.12 WATER ABSORPTION (SAE J140
17、1) Hose assemblies at the minimum and maximum of the compression range for hose crimp diameter must meet the requirements of this specification for Burst Strength and Tensile strength after Water Absorption. 3.13 HOT IMPULSE (SAE J1401, 150 cycles) No leakage is permitted during the 2 minute hold pe
18、riod at 27.6 MPa. Minimum burst pressure of 34.5 MPa Test hose assemblies at the minimum and maximum of the compression range for hose crimp diameter. 3.14 HEAT AGING AND COLD BEND RESISTANCE (Ref. ASTM D 573) No cracks when bent around mandrel after heat aging and cold bending. Test Method: Heat ag
19、e two hose assemblies for 10 days at 125 +/- 2 C. Remove from the oven and allow them to cool to room temperature for 6 - 12 hours. Chill hoses and a 76 mm (3.0in) diameter mandrel for 48 hours in a chamber maintained at -46 to -48 C. Without removing from the chamber, bend the hose 180 around the m
20、andrel within 3 - 5 seconds. Remove the hose from the cold chamber and allow it to return to room temperature for 1 - 6 hours. Wrap the hose around a 76mm diameter mandrel and inspect, without magnification, for cracks or breaks in the wire braids and in the inner tube. ENGINEERING MATERIAL SPECIFIC
21、ATIONWSS-M99P26-A2/A3 Printed copies are uncontrolled Copyright 2008, Ford Global Technologies, LLC Page 4 of 4 3.15 MOISTURE TRANSMISSION (SAE J1873) Measure moisture level after a 168 h exposure. Report Percent Test Method: Use the method outlined in SAE J1873 with the following exceptions. Para 6
22、.1.2 Fill six hose assemblies and wrap the plug threads with Teflon tape before reassembling. Para 6.3 Use a circulating heated water bath instead of an oven and a glass container. Use tap water instead of deionized. Para 6.3.1 Do not immerse the ends of the hoses. Allow 2-3 cm of each end to be abo
23、ve the water line. 4 GENERAL INFORMATION The information given below is provided for assistance in understanding the requirements. Test methods based on SAE J 1401 rev Jun2003 and SAE J1873 rev Oct2000. The following conversions can be used to compare values with FMVSS requirements. Volumetric Expan
24、sion 0.590 cc/m at 6.9 Mpa = 0.18 cc/ft at 1000 psi 0.787 cc/m at 10.3 Mpa = 0.24 cc/ft at 1,500 psi 1.575 cc/m at 20 Mpa = 0.48 cc/ft at 2,900 psi The following tests are present in the rubber brake hose specification WSS-M96D4-B but do not apply to this hose construction. ADHESION, min 1.4 N/mm (ASTM D 413, Ring Specimen) IMMERSION IN OIL, max (ASTM D 471) Maximum allowable hose O.D change 0 to 15% Test Method: Cut two 76 mm long pieces of hose and plug the ends. Immerse for 48 h at 70 +/- 2 C in IRM 903 oil.
