NHTSA Engineering Analysis EA98024

In January 1998, GM issued the technical service bulletin describing conditions which may result in fuel leakage from the emission vapor canister.According to the bulletin, when the subject vehicles are parked on an incline, with a full tank of gasoline, fuel can flow into the vapor canister.The remedy is to replace of the vapor canister, both rollover valve assembles, and the associated piping.In April 1998, ODI opened Service Query 98-005 to understand GM's rationale for issuance of a service bulletin on a matter that appeared to result in fuel leakage, an issue that is usually address by conducting a safety recall campaign.On November 10, 1998 the SQ was elevated to an Engineering Analysis (EA98-024) to investigate an alleged defect in the fuel tank rollover valve system in certain 1996 through 1997 Chevrolet Trucks and OMC Full Size 010-030 panel and passenger vans.