RAM 1500 Van V8-5.9L VIN Z (1998)
Fuel Filler Cap: Description and Operation
DESCRIPTION
The loss of any fuel or vapor out of filler neck is prevented by the use of a pressure-vacuum fuel tank filler tube cap.
OPERATION
Relief valves inside the cap will release fuel tank pressure at predetermined pressures. Fuel tank vacuum will also be released at predetermined
values. This cap must be replaced by a similar unit if replacement is necessary. This is in order for the system to remain effective.
CAUTION: Remove fuel tank filler tube cap before servicing any fuel system component. This is done to help relieve tank pressure. If equipped
with a California emissions package and a Leak Detection Pump (LDP), the secondary seal below the fill cap must be pressed (opened) to relieve
fuel tank pressure.
