Webasto Air Top 2000 ST B Installation Instructions Manual page 18

Fuel supply
7.1. Vehicles with carburettor engines
The fuel may only be extracted using the special Webasto fuel extractor
(see Figure 9) as close to the tank as possible. The connect may be made
in either the supply or return line, in which case the return line must lead
almost to the base of the tank (see Figure 10).
The fuel extractor must be fitted in such a way that any air or gas bubbles
are automatically discharged towards the tank (see Figure 9).
from tank
to metering pump
Fig. 9: Webasto fuel extractor
The fuel extractor should not be located near the engine, as gas bubbles
may form in the lines on account of heat radiated from the engine. This
may cause problems during combustion.
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to engine
7.2. Vehicles with injection engines
When installing the heater in a vehicle with fuel injection system, it is im-
portant to establish whether the vehicles fuel pump is located inside or
outside the tank.
If the fuel pump is located inside the tank, fuel can only be extracted from
the return line using the Webasto fuel extractor (see Figure 9), in which
case it must be checked to ensure that the fuel return pipe in the tank ter-
minates near the bottom of the fuel tank (see Figure 10 for details of the
minimum distance from the bottom of the tank). If this is not the case We-
basto fuel extractor (see Figure 10, 11 and 12) may be used.
If the fuel pump is installed outside the tank, the fuel connection may also
be made between the tank and the fuel pump, again using only the We-
basto fuel extractor (see Figure 9).
7.3. Vehicles with diesel engines
The fuel must be taken from the vehicle fuel tank or from a separate tank
(see Figs. 9, 10 and 11). This separate fuel pick-up precludes any effect of
pressure.
Hole pattern
Fig. 10: Webasto tank connector
Air Top 2000 ST
Only use a tank connector if the fuel
tank is made from metal
Minimum distance 25 mm