Webasto Air Top 2000 ST B Installation Instructions Manual page 16

Air Top 2000 ST
7.1. Vehicles with carburettor engines
The fuel may only be extracted using the special Webasto fuel extractor
(see Figure 10) 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 11).
The fuel extractor must be fitted in such a way that any air or gas
bubbles are automatically discharged towards the tank (see Figure 10).
from tank
to metering pump
Fig. 10: 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.
to engine
7.2. Vehicles with injection engines
When installing the heater in a vehicle with fuel injection system, it is
important to establish whether the 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 10), in which
case it must be ensured that the return line continues almost to the
bottom of the tank (see Figure 11 for details of the minimum distance
from the bottom of the tank). If this is not the case Webasto fuel extractor
(see Figure 11, 12 and 13) 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
Webasto fuel extractor (see Figure 10).
7.3. Vehicles with diesel engines
The fuel must be taken from the vehicle fuel tank or from a separate tank
(see Figs. 10, 11 and 12). This separate fuel pickup precludes any effect
of pressure.
Hole pattern
Fig. 11: Webasto tank connector
Fuel supply
Only use a tank connector if the fuel
tank is made from metal
Minimum distance 25 mm
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