Rolls-Royce Remote Oil Filler Valve Bulletin - Code7700

OIL - REMOTE OIL FILL VALVE - INTRODUCTION OF A NEW REMOTE OIL FILL VALVE (ROFV) WITHA MODIFIED PISTON AND VALVE SEAT - MOD.79-16981. Planning InformationPrinted in Great BritainA. Effectivity(1) Gulfstream IV-X.Tay 611-8C Engines, prior to Engine Serial Number 85120.Non-Modular.B. Concurrent RequirementsNone.C. Reason(1) ProblemOil leakage from the Remote Oil Fill Valve (ROFV) overflow port can occurafter oil filling operation. The oil leakage is caused by the valve notclosing fast enough after the oil filling operation, because of acondition known as 'hydraulic lock'. The overflow passage then staysslightly open and the accessory gearbox internal air pressure thatdevelops during engine operation causes the oil to be pushed out of theROFV overflow port to overboard.(2) EvidenceThis was identified on engines in service.(3) SubstantiationThe changes introduced by this Service Bulletin were the subject ofsatisfactory engineering analysis and tests. This Service Bulletincomplies with the applicable engine certification basis.(4) ObjectiveIntroduction of this Service Bulletin is designed to maintain reliability.Jul.14/06Jul.14/06TAY−79−1698Page 1 of 15