Elastomeric Vacuum Brake Hose
|Publication Date:||1 September 2016|
This specification covers light wall vacuum brake hoses for use in power braking systems of vehicles.
Material Description. Materials covered by this specification are divided into two (2) Types. It is possible for a hose to be approved to more than one (1) Type.
• Type A1 hose is suitable for use to temperatures of +125 °C continuous exposure, and +150 °C excursion exposure.
• Type A2 hose is suitable for use to temperatures of +125 °C continuous exposure, and +150 °C excursion exposure but higher compression set values than Type A1.
• Type B1 hose is suitable for use to temperatures of +150 °C continuous exposure and +175 °C excursion exposure.
• Type B2 hose is suitable for use to temperatures of +150 °C continuous exposure and +175 °C excursion exposure with higher changes in properties than Type B1.
Construction. The hose shall consist of a smooth tube of Ethylene Propylene Diene Monomer (EPDM) elastomer reinforced with a ply or plies of braided, knit, spiral, or woven polyester or other vendee approved fabric and furnished with a cover of EPDM elastomer. Hoses shall be black unless otherwise specified. Hose shall conform to the dimensions and tolerances listed in Appendix A; Table A1. The hose shall be legibly marked with the following information:
• Symbol DOT.
• Nominal inside diameter (expressed as fraction of inch).
• Hose manufacturer's code identification.
• Date code; the symbol VL; and the GM specification number (GMW16501).
Such markings shall be printed parallel to the axis in white or blue block letters not <3 mm high and shall be repeated at intervals of 150 mm maximum. The symbol DOT constitutes certification by the hose manufacturer that the hose assembly conforms to Federal Motor Vehicle Safety Standard (FMVSS 106). The date code shall consist of six (6) digits: The first two (2) digits shall represent month (01 through 12) of the year, the next two (2) digits shall represent the day of the month (01 through 31); and the last two (2) digits shall be the last two (2) digits of the year. In addition, each hose manufacturer shall incorporate into the construction of the hose, identification yarn as assigned by the Rubber Manufacturers Association (RMA).
Material Identification and Marking. To properly define the hose, the material specification number (GMW16501) is to be referenced. The vacuum hose marking must conform to requirements specified in government regulations, such as FMVSS 106. The vacuum hose must also meet requirements for vacuum brake hose marking specified in GMW16501.
For China usage, the supplier is responsible to contact the China Quality Certificate Center for China Compulsory Certification (CCC) activities, and ensure the vacuum hose/tubes meet the CCC requirements, reference CNCA-C11-12: 2014. All saleable parts shall have CCC markings after proper authorization which includes both a CCC label and the related GB 16897 test standard. A copy of the certificate for the part shall be sent to GM Engineering before Production Part Approval Process (PPAP). This applies to both production parts and parts for service.