MANN FILTER has published a document explaining why MANN FILTER in-line fuel filters WK 939, WK 939/2, WK 12 001 and WK 12 004 feature a ‘break-through’ plastic bung.
In the document, MANN-FILTER said: “MANN-FILTER in-line fuel filters including WK 939, WK 939/2, WK 12 001 and WK 12 004 are equipped to take a removable sensor that warns of excessive water ingress.
“However, as the sensor may not be fitted to all vehicles within a model range, these fuel filters may employ a ‘break-through’ plastic blank within the mounting hole.”
Filter fitment with water sensor
- Remove the plastic bung (where fitted) from the threaded water sensor mounting hole.
- Thread the water sensor into the mounting hole on filter (Figure 1).
- Continue to turn the sensor until a resistance is felt and a ‘crack’ is heard – don’t worry, this is just the sensor tip breaking through the plastic blank (Figure 2).
- Tighten the sensor to the vehicle manufacturer’s torque specification.
- Reconnect sensor wiring.
Filter fitment without water sensor
- Leave the plastic bung (where fitted) in the mounting hole and fit the filter as normal.
For further information about MANN-FILTER click “more details” below.