ISO INTERNATIONAL STANDARD 13556 First edition 1998-12-01 Road vehicles Localization of exhaust system leaks and equipment specifications Véhicules routiers Localisation des fuites de la ligne d'echappement et spécificationsde l'équipement ISO Reference number ISO13556:1998(E) IHSunder Not for Resale ISO 13556:1998(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 Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International a vote. International Standard ISO 13556 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 5, Engine tests. @ISO1998 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International OrganizationforStandardization Case postale 56 . CH-1211 Geneve 20 · Switzerland Internet iso@iso.ch Printed in Switzerland se from IHS Not for Resale INTERNATIONAL STANDARD @ISO ISO 13556:1998(E) Road vehicles Localization of exhaust system leaks and equipment specifications 1 Scope This International Standard specifies a method to verify the gas tightness of the exhaust system of road vehicles equipped with an international combustion engine. It is primarily intended to establish a method to detect and localize exhaust system leaks in order to improve the regulations. The users of this International Standard are warned that: a) certain engines with high valve overlaps camshaft events, especially engines with eight or more cylinders, may not have all exhaust valves closed when the engine is stopped. This issue may cause the leak test to fail. This situation could be corrected by the disassembly of the exhaust valve actuation mechanism using the vehicle or engine manufacturer's recommended procedure; b) national regulations on the subject of pressurizing should be checked before testing; c) detected leakage can be quantified under certain test conditions. This International Standard also specifies the measurement apparatus and necessary devices. This method is particularly recommended for: a)automotive workshops, laboratories before any emission tests, c) testing and diagnostic stations. 2 Definitions For the purposes of this International Standard, the following definitions apply. 2.1 exhaust system 2.2 leaks all outward exhaust gas flow or inward air flow which can affect the exhaust emission measurement results 1) Iso 3929:1995, Road vehicles- Measurement methods for exhaust gas emissions produced during inspection or maintenance. ational Organization for Standardization 1 Copyright Inte