W 250 Pickup L6-359 5.9L DSL (1989)
Rollover/Pressure Relief Valve: Description and Operation
Fuel Gauge Sending Unit
This valve is located on top of the fuel tank, and its primary purpose is to seal off the fuel tank in the event of accidental vehicle rollover. The relief
valve portion of the valve allows fuel vapors to vent to the atmosphere when the fuel tank pressure exceeds the calibrated sealing valve setting.
