Comanche 4WD L4-150 2.5L VIN P MFI (1991)
Fuel Tank Pressure Release Valve: Description and Operation
Roll Over Valve
The dual function pressure relief/rollover valve relieves fuel tank pressure under normal operating conditions, and prevents fuel flow to the vapor
canister through the vent hose in the event of a vehicle rollover. The valve consists of the following parts:
^
Orifice with guide plate
^
Plunger
^
Spring
The pressure relief/rollover valve is mounted on top of the fuel tank in a normally open position. In the open position, fuel vapors from the tank travel to
the vapor canister. In the event of a vehicle rollover, the valve becomes inverted and the plunger is forced against the guide plate preventing raw fuel
from flowing through the valve orifice into the vent tube.
