Chrysler Technology Center
November 1, 1995
Chief, Criteria Pollutants Branch
California Air Resources Board
2020 L Street Sacramento, CA 95814
Dear Mr. Simeroth,
As part of its program to evaluate the performance of California Phase 2 reformulated gasoline (CP2), Air Resources Board (ARB) inspectors have examined the fuel system integrity. Vehicles operating on both conventional gasoline and CP2 were examined. During the course of these examinations, the inspectors identified a number of "seeps" in vehicles from both the conventional and CP2 populations. As we understand it, a "seep" may be a wet spot or a stain near a gasket, seal, or fitting, suggesting that fuel may have "seeped" from this area under some operating conditions. A "seep" is differentiated from a "drip" or "leak" by the fact that no actual fuel is observed at the time of inspection.
Our task group has been asked to evaluate these "seeps" to determine whether, collectively, they appear to be abnormal. To that end, we have visited some of the California fleets operating on both conventional and CP2 gasoline, and have evaluated some similar mileage and age vehicles here in the Detroit area. Based on these evaluations, we conclude that the "seeps" do not represent an abnormal condition. In particular, many of the seeps that were evaluated in the California fleets, may not be fuel related at all. Some appeared to be motor oil, others possibly brake fluid or coolant. In both the California and Michigan-based vehicles, carburetors, fuel pumps, and fuel filters seem to be areas where dust and grime accumulate, without any evidence of actual fuel leaks. Also, similar accumulations of "grime" were identified near PCV and EGR fittings, coolant and power steering fluid hoses and lines, and master cylinders.
Based on a review of these findings with my colleagues at Ford and General Motors, the task group recommends that the "seeps" identified in both the conventional and CP2 fueled fleets be considered "not fuel related", and removed from further consideration in the analysis of fuel-related incidents in the program.
Loren K. Beard, PhD
Jerry Barnes, General Motors
Brian Rippon, Ford