Biological contamination in fuels, Symptoms, Cause – JLG 600SC_660SJC Service Manual User Manual
Page 101: Preventive measures, Fuel additives, Biological contamination in fuels -65

SECTION 3 - CHASSIS & TURNTABLE
3121607
– JLG Lift –
3-65
Biological Contamination In Fuels
SYMPTOMS
The following symptoms may indicate a fuel tank is contami-
nated by micro-organisms:
• Internal tank corrosion,
• Filter blockage and associated loss of power due to gel-like
deposits on the fuel filter (especially after long standstills)
CAUSE
Micro-organisms (bacteria, yeasts, funguses) can form bio-
sludge under unfavorable conditions (favoured particularly by
heat and water).
Penetration by water is usually caused by condensation of water
in the air. Water does not dissolve in fuel so penetrating water
collects at bottom of the tank. Bacteria and funguses grow in the
watery phase, at phase boundary to the fuel phase, from which
they draw their nutrition. There is an increased risk especially
with bio-diesel (FAME).
PREVENTIVE MEASURES
• Keep storage tank clean. Perform regular cleaning of the
tank by specialist companies
• Installation of fuel pre-filters with water traps, especially in
countries with frequently fluctuating fuel qualities and high
percentage of water.
If the fuel system and storage tank have already been attacked
by micro-organisms. Biocide must be dosed according to the
manufacturer's specifications.
• Avoid direct exposure of the storage tank to sunlight
• Use smaller storage tanks with corresponding low dwell
times of the stored fuel
FUEL ADDITIVES
The use of fuel additives is not permitted. The flow improvers
mentioned above are an exception. Use of unsuitable additives
will result in loss of warranty.