User's Manual

Thermo 90 S / Thermo 90 ST 8 Service work
805
8.6.2.1 Fuel extraction
Vehicles with diesel engines
The fuel must be taken from the vehicle fuel tank or from
a separate tank (Figs. 803, 804 and 805).
Fig. 803 Webasto fuel extractor
NOTE
The fitting must be made from metal!
Fig. 804 Fuel extraction from the plastic tank
(extraction through tank drain screw)
Fig. 805 Fuel extraction from the plastic tank
(extraction through tank fitting)
NOTE
Deburr the cut on the fuel extractor after sawing it off and
remove any metal chips
Vehicles with petrol engines
The heater must be integrated into the return line of fuel
systems in carburettor and injection engines with a return
line.
In carburettor engines without a return line the heater
must be integrated into the fuel system in the supply line
between the fuel tank and the vehicle pump.
NOTE
• A fuel feed line can normally be identified by the fact
that a fuel filter is installed in it.
• If there is an evaporation tank in the vehicle’s fuel
system, the fuel must be extracted upstream of the
evaporation tank.
Fuel may only be taken from the supply or return line
using the special Webasto fuel extractor
(Fig. 806). The
fuel extractor must be fitted in such a way that any air or
gas bubbles are automatically discharged towards the
tank (Fig. 806). Air or gas bubbles may be produced in the
vehicle’s fuel line if there are leaks in the carburettor or
vehicle fuel pump or if the ambient temperature is higher
than the evaporation temperature of the fuel.
> 25 mm
25
Hole
pattern
Only use a fuel
extractor with
metal fuel tanks
Sealing ring
Plastic tank
Sealing ring
Tank fitting
Fuel extractor