Webasto Thermo 90, Руководство по ремонту

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8 Servicing Thermo 90
806
The fuel tap should not be located in the engine
compartment because the radiation of engine heat may
cause gas bubbles to build up in the fuel lines causing
malfunctions in the combustion operation.
When installing the heater in vehicles with fuel injection
system the fuel pump's location within or outside the fuel
tank must be investigated first.
If the fuel pump is fitted inside the fuel tank, the fuel may
be tapped only from the return line ensuring that the return
line is routed almost to the tank floor. If this is not the case
the fuel line may be lengthened.
In case of a fuel pump mounted externally to the tank the
fuel tap can be located between fuel tank and fuel pump.
8.6.2.2 Fuel Lines
Fuel lines may only be steel, copper, or plastic lines
made of unhardened, light and temperature stabilised
PA 11 or PA 12 (e.g. Mecanyl RWTL) according to
DIN 73378. As in most cases a permanently rising fuel
line routing cannot be ensured, the inner diameter must
not exceed a certain value. Starting from an inside
diameter of 4 mm, air or gas bubbles accumulate resulting
in malfunctions should the lines be descending or having
sags. The diameters specified in Fig. 802 ensure a
non-accumulation of air bubbles.
A descending line routing from the dosing pump to the
heater should be avoided.
Loose fuel lines must be secured in order to avoid
sagging. The installation must ensure protection against
stone impacts and
undue temperatures (exhaust line).
The fuel line joints are to be secured against loosening
with hose clamps.
Connection of 2 Pipes with Hose
The proper connection of fuel lines with hoses is shown in
Fig. 806.
Fig. 806 Pipe/Hose Connection
8.6.3 Dosing Pump
The dosing pump is a combined delivery, dosing, and
shut-off system and is subject to certain installation
criteria (see Figs. 802 and 807).
Thermo 90, 12 Volt – Fuel
Thermo 90, 12 Volt and 24 Volt – Diesel DP 30
Installation Position Horizontal only
Fig. 807 Dosing Pump, Installation Location and
Attachment
correct
wrong
clamp
bubble bubble
0-90°
0°
0-90°