FUEL ODOR REAR-TANK SEAL LEAK (REPLACE CAP)

SUBJECT: FUEL FILLER CAP CROSS THREADING (REPLACE CAP)

VEHICLES AFFECTED: 1985-91 'F' CAR

CONDITION:

Comments of fuel odour and rear quarter panel staining in the area of the fuel filler door may be received on 1989-91 F-Cars. This condition has occasionally been noted after the vehicles fuel tank has been over filled, but does not occur after every refilling.

CAUSE:

Inadvertent cross threading of fuel filler cap may provide false indication (clicking/racheting sound) that cap has been properly installed. During proper installation, cap will rotate freely for at least two (2) complete revolutions prior to seal of cap contacting filler neck sealing surface, at which time additional rotation will generate clicking/racheting sound.

CORRECTION:

Replace existing fuel filler cap with new cap, P/N #10164142. The lead and thread characteristics of the new cap have been modified to minimize potential for cross threading to occur.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.