Service Information: Fuel filter heater retrofit option

For diesel vehicles, the fuel flow behavior may be impaired under unfavorable conditions, e.g. extended cold periods, low annual mileage and therefore summer fuel remains longer in the fuel system.

This in turn means that paraffin separation (fuel jellification) may cause starting problems in the diesel fuel as a consequence of a clogged fuel filters.

In instances of fuel jellification, the vehicle is to be heated in a heated workshop to temperatures higher than 0 °C and the fuel filter is to be replaced.

With immediate effect, it is possible to retrofit a fuel filter heater for engine 646 in model 906.

 To improve the cold flow behavior of diesel fuel, flow improver should be added to the fuel in operating conditions below -20 °C (preferably before this temperature is reached). Information regarding this can be found in the Specifications for Operating Fluids, Sheet 137.0 and 137.1.

The installation instructions with the respective time allowance is stored under the specified document number in the WIS/ASRA.

In the most recently published installation instructions, the part number for the parts kit is incorrect. For the corrected part number, please refer to the parts ordering note listed below.

The updated installation instructions will be published in WIS release 01/2011.

 Retrofitting of the fuel filter heater must be documented in VeDoc in the AO Texts mask under DG 07 (Carburetor/injection system) as follows:

Fuel filter heater retrofitted as per AN07.00-D-0001A

Heated fuel filter

A 642 090 31 52"

 This retrofit is not covered by the terms of the warranty.

Parts ordering notes