F 350 4WD Super Duty V8-6.4L DSL Turbo (2008)
Fuel Tank Vent: Customer Interest
Fuel System - WIF Lamp ON/No Driveability Issues
TSB 09-14-4
07/27/09
WIF LIGHT ON - NO DRIVABILITY SYMPTOMS
WATER IN AFT FUEL TANK DUE TO SNOW AND ICE
BUILD UP IN FUEL TANK VENT AREA - 6.4L, 6.0L,
AND 7.3L DIESEL ENGINE
FORD:
1999-2010 F-350, F-450, F-550
This article supersedes TSB 07-24-4 to update the vehicle model years and Service Procedure.
ISSUE
Some 1999-2010 vehicles equipped with a 6.4L 6.0L, or 7.3L diesel engine and a 40-gallon (151.4L) fuel tank behind the rear axle, may exhibit water in
the fuel tank. This is due to snow and ice accumulating around the mushroom vent cap, melting, and being pulled into the tank through the mushroom
cap.
ACTION
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
Typically only 1-2 ounces of water will get into the tank if the above condition is present and will be caught by the horizontal fuel conditioning module
(HFCM). Symptoms for this issue are Water In Fuel (WIF) light on, this concern has not resulted in any drivability concerns. The FCM/HFCM acts as a
primary fuel filter/water separator which removes both water and impurities from the fuel. The engine-mounted fuel filter and the FCM/HFCM filter
should be changed at the recommended service interval. Refer to the scheduled maintenance information in this supplement for more information.
Draining of the WIF module assembly should be done whenever the warning light comes on and is the responsibility of the owner.
This procedure is not applicable to rain, road splash or incomplete chassis cabs sitting in storage. The vent will only ingest water if the vent is
surrounded by ice or snow.
1. Remove the existing mushroom cap installed on the vent port of the fuel tank and discard.
2. Install the hose end of the new vent line assembly onto the vent port and secure with the constant tension clamp.
3. Route the new vent line assembly forward, on top of the tank, to the number 5 crossmember, and under the fuel lines (Figure 1).
4. Secure the end of the new vent line assembly to the crossmember with the tie strap, at the large circular hole in the middle of the vehicle.
5. Install the new mushroom cap at the end of the vent line. Be sure the cap is positioned horizontally to prevent water from collecting in the cap.
