Durango 4WD V8-5.9L VIN Z (1998)
Fuel Filler Cap: Description and Operation
Pressure-Vacuum Filler Cap
PURPOSE
The fuel filler cap is used to relieve excess fuel tank pressure or vacuum and prevents loss of any fuel or vapor out of the filler neck.
OPERATION
Relief valves inside cap will release only under significant pressure of 6.58 to 8.44 kPa (1.95 to 2.5 psi). The vacuum release for all gas caps is
between 0.97 and 2.0 kPa (0.14 and 0.29 psi).
NOTE: This cap must be replaced by a similar unit if replacement is necessary. This is in order for the system to remain effective.
NOTE: It is normal to encounter an air pressure release when removing the fuel filler cap.
