jcb 540-170, Service Manual

Page: 78 / 149

Section 1-7 - General Information
Fuel
Acceptable and Unacceptable Fuels
1-7-8 1-7-8
9803/3750-05 (1-08-00)
Effects of Fuel Contaminates
The effect of dirt, water and other contaminants in diesel
can be disastrous for injection equipment:
– Dirt - A severely damaging contaminant. Finely
machined and mated surfaces such as delivery
valves and distributor rotors are susceptible to the
abrasive nature of dirt particles - increased wear will
almost inevitably lead to greater leakage, uneven
running and poor fuel delivery.
– Water - water can enter fuel through poor storage or
careless handling, and will almost inevitably
condense in fuel tanks. The smallest amounts of
water can result in effects that are just as disastrous
to the fuel injection pump as dirt, causing rapid wear,
corrosion and in severe cases, even seizure. It is
vitally important that water is prevented from reaching
the fuel injection equipment. The filter/water trap must
be drained regularly.
– Wax - Wax is precipitated from diesel when the
ambient temperature falls below that of the fuel's
cloud point, causing a restriction in fuel flow resulting
in rough engine running. Special winter fuels may be
available for engine operation at temperatures below
0°C (32°F). These fuels have a lower viscosity and
limit wax formation.
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