ISO INTERNATIONAL 4925 STANDARD Third edition 2020-07 Road vehicles Specification of non- petroleum-based brake fluids for hydraulic systems Vehicules routiers- Specifications pour liquides de frein a base non petrolierepoursystemeshydrauliques Reference number IS04925:2020(E) ISO @IS02020 IS0 4925:2020(E) COPYRIGHTPROTECTEDDOCUMENT IS02020 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting below or Iso's member body in the country of the requester. ISo copyright office CP 40i: Ch.de Blandonnet 8 CH-1214 Vernier,Geneva Phone: +4122749 0111 Email: [email protected] Website: www.iso.org Published in Switzerland i @ IS0 2020 - All rights reserved IS0 4925:2020(E) Contents Page Foreword iv Introduction. .V 1 Scope. 1 2 Normative references 1 3 Terms and definitions .2 4 Materials 5 Specifications. .2 6 Test methods. 4 6.1 Viscosity. 4 6.1.1 General 4 6.1.2 Repeatability (single analyst) 4 6.1.3 Reproducibility (multi-laboratory) 4 6.2 Equilibrium reflux boiling point (ERBP) 5 5 6.2.1 General 6.2.2 Preparation of apparatus 5 6.2.3 Test procedure 5 6.2.4 Repeatability (single analyst) 5 6.2.5 Reproducibility (multi-laboratory) 5 6.2.6 WetERBPtest 6 6.3 pH .9 6.4 Fluid stability. .9 High-temperature stability 9 6.4.1 6.4.2 Chemical stability. 10 6.5 Corrosion 10 6.5.1 Metal strip characteristics priortotesting 10 6.5.2 Preparation of joints 10 6.5.3 Test procedure 11 6.6 Fluidity and appearance at low temperatures. 11 6.6.1 At-40°Cfor144h 11 6.6.2 At -50 °C for 6 h. 11 6.7 Water tolerance 12 6.7.1 At -40 °C for 22 h 12 6.7.2 At 60 °C for22h. 12 6.8 Compatibility/miscibilitywithIS04926fluid 12 6.8.1 At-40°Cfor 22 h 12 6.8.2 At60°Cfor22h 12 6.9 Resistance to oxidation. 12 6.10 Effect on rubber. 13 6.10.1 Test procedures. 13 6.10.2 Repeatability (single analyst) 14 6.10.3 Reproducibility (multi-laboratory) 14 6.11 Reserve alkalinity according to ASTM D 1121 14 Annex A (normative) ISO styrene-butadiene rubber (SBR) brake cups for testing brake fluid .15 AnnexB (normative) Corrosion test strips .18 AnnexC(informative)Corrosionstripassembly .19 AnnexD (normative) Standard ethylene,propyleneand diene (EPDM) terpolymer rubber slabstock .20 Annex E (normative) Triethylene glycol monomethyl ether (TEGME) brake fluid grade ..22 Bibliography .25 iii IS0 2020-All rights reserved