1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14362 Stricter Testing of Brake Hose Ageing Resistance Copyright 2012 General Motors Company All Rights Reserved September 2012 Originating Department: North American Engineering Standards Page 1 of 4 1 Scope Note: Nothing in this standard supercede
2、s applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. Note: The Stricter Aging Resistance Test is not required for hoses incorporating rayon reinforcement. 1.1 Purpose. This test procedure shall be use
3、d to simulate stricter ageing of brake hoses in conjunction with brake fluid and a saturated steam atmosphere. The parts shall then be subjected to further tests to check their good working order. 1.2 Foreword. Not applicable. 1.3 Applicability. Not applicable. 2 References Note: Only the latest app
4、roved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. GMW3056 GMW14361 3 Resources 3.1 Facilities. Not applicable. 3.2 Equipment. 3.2.1 Test Equipment. Container to hold brake fluid, contents approximately 350 cm (See
5、Figure 1, similar to GMW14361). 3.3 Test Vehicle/Test Piece. 3.3.1 Test Material. The number of brake hoses to be aged depends on the number of pre-aged brake hoses required for other test procedures. 3.4 Test Time. Not applicable. 3.5 Test Required Information. Not applicable. 3.6 Personnel/Skills.
6、 Not applicable. 4 Procedure 4.1 Preparation. Not applicable. 4.2 Conditions. 4.2.1 Environmental Conditions. Not applicable. 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certifi
7、cates, reports, etc. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14362 Copyright 2012 General Motors Company All Rights Reserved Sept
8、ember 2012 Page 2 of 4 4.3 Instructions. 4.3.1 Test Procedure. 4.3.1.1 The brake hoses shall be fastened, suspended vertically, with their female fitting to a container (See Figure 1). 4.3.1.1.1 The other end (banjo fitting or female fitting) of the brake hoses, shall be sealed with a suitable screw
9、 plug. 4.3.1.1.2 Then the container shall be filled with brake fluid (use brake fluid to GMW3056 unless otherwise specified). 4.3.1.1.3 The screw plug of each brake hose shall be opened until brake fluid emerges to ensure that the hose is filled with brake fluid without air bubbles. The ends shall t
10、hen be securely screwed. After all air is removed from the brake hoses, the container should still be filled approximately 50% with brake fluid, and be securely sealed also. Figure 1: Container to Hold Brake Fluid 4.3.1.2 The container - brake hose assembly shall be installed in an autoclave. Storag
11、e conditions: Storage period: 1344 h (56 days) Relative air humidity: 100% saturated steam atmosphere Storage temperature: +105 2 C The assembly shall then be allowed to cool and the brake fluid shall be removed. The ageing process may be interrupted in reasonable cases. Copyright General Motors Com
12、pany Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14362 Copyright 2012 General Motors Company All Rights Reserved September 2012 Page 3 of 4 5 Data 5.1 Calculations. N
13、ot applicable. 5.2 Interpretation of Results. Not applicable. 5.3 Test Documentation. 5.3.1 Evaluation and Rating. 5.3.1.1 After ageing, the brake hoses shall be X-rayed to determine whether a chemical reaction has taken place between water, the boric acid of the brake fluid and the fabric. This can
14、 be recognized by the formation of a gel-like substance between the elastomeric lining and the 1st fabric layer (reinforcement), which bulges the lining towards the inside of the hose, see Figure 2 and Figure 3. Figure 2: Example of Bulge Figure 3: Example of Bulge 5.3.1.2 Alternatively, constrictio
15、n of the hose shall be checked by holding the assembly vertically at one fitting and inserting a spherical constriction test probe as defined in Figure 4 into the end of the upper fitting. The probe shall fall through the assembly without assist. Manual straightening of the hose is permissible; no o
16、ther manipulation of the assembly is allowed. The size of the spherical constriction test probe for the hose tested shall be as defined in Table 6 of GMW3056. 5.3.1.3 Afterwards, the burst pressure must be determined according to GMW3056. Requirement: See GMW3056. Copyright General Motors Company Pr
17、ovided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14362 Copyright 2012 General Motors Company All Rights Reserved September 2012 Page 4 of 4 Figure 4: Spherical Constriction
18、Test Probe 5.4 Report. With reference to this test procedure the results of the measurements shall be presented in a test report. 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with its u
19、se. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. Not applicable. 8 Coding System This
20、standard shall be referenced in other documents, drawings, etc., as follows: Test to GMW14362 9 Release and Revisions This standard was originated in September 2005. It was first approved by the Global Elastomers Team in December 2006. It was first published in November 2007. Issue Publication Date Description (Organization) 1 NOV 2007 Initial publication. 2 SEP 2012 5 Year Refresh. (Global Elastomers GSSLT) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
