ISO INTERNATIONAL STANDARD 20918 First edition 2007-10-15 Road vehicles Braking threshold pressures for heavy commercial vehicle combinations with fully pneumatic braking systems - Test with roller brake tester Vehicules routiers - Seuil de pressions de freinage pour les ensembles routiers lourds a systemes de freinage uniquement pneumatiques- Essais sur banc d'essai a rouleaux Reference number ISO 20918:2007(E) @ ISO 2007 by IHS under ted without license from IHS Not for Resale ISO 20918:2007(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below COPYRIGHTPROTECTEDDOCUMENT @ISO2007 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, IsO's member body in the country of the requester. ISO copyright office Case postale 56. CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland @ ISO 2007 - All rights reserved edwithoutlicense from IHS Not for Resale ISO 20918:2007(E) Contents Page Foreword iv Introduction 1 Scope 2 Normative references 3 Terms and definitions 4 Systemthresholdpressurerecommendation 5 Apparatus 6 Procedure.... 6.1 General.. 6.2 Vehicle test for truck and semi-trailer tractor.. 6.3 Vehicle test for trailer....... Annex A (informative) Report form for the roller brake test if printouts not available . Annex B (informative) Examples of roller brake test printouts for the measurement of system threshold pressure 6 Bibliography CopyrightInternatinal Oorganizain forstandardizalirnghts reserved ii se from IHS Not for Resale ISO 20918:2007(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with isO, also take part in the work. iso collaborates closely with the International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 20918 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 2, Braking systems and equipment. ISo 2007 - All rights reserved ional Organization for Standardizatior ISO 20918:2007(E) Introduction The compatibility between motor vehicles and trailers relates not only to stability, but also to wear balance, or rather,to wear optimization. Wear optimization and low adhesion utilization requires good braking balance between axles in the pressure all brakes start to develop a braking for