K 20 3/4 Ton Pickup 4WD V8-379 6.2L DSL VIN J FI (1983)
Fuel: All Technical Service Bulletins
Diesel Fuel System - Contamination
Number:
83-I-113
Section:
VI
Date:
September, 1983
Subject:
DIESEL FUEL SYSTEM CONTAMINATION - ALL DIESEL ENGINES
TO:
ALL CHEVROLET DEALERS
Several forms of fungi and other microorganisms can survive and multiply in diesel fuel. The microscopic growths can occur in all areas of the fuel
handling system storage tanks, pump trucks delivery lines and fuel tanks. These fungi grow into long strings, and form large mats of globules. The
growth appears slimy, and usually is black, green or brown, although it may be any color. It may grow throughout the fuel, or at the interface area
between the fuel and water bottom layer. As the fuel is agitated, for instance during filling of the retail outlet storage tanks, fungal growth is distributed
throughout the fuel system, and if a vehicle is fueled at that time, its fuel tank could receive contaminated fuel.
Fungi need only trace amounts of minerals and water to sustain their growth, and use the fuel as their main energy source. As they grow and multiply,
they chemically alter the fuel to produce water, sludge, acids and other products of metabolism. Where they cling, they hold water and waste products
against metal and other surfaces, thereby leading to corrosion. The most common condition is fuel filter plugging; however, the various metal
components of the fuel system including the fuel tank and the injection pump can corrode.
Several companies market products which are claimed to control microbial growth in diesel fuel. One such product found to be effective is BIOBOR(R),
marketed by U.S. Borax and Chemical Corporation. It is available in a form suitable for use in treating an automotive fuel system under the trade name
BIOBOR(R) Diesel Doctor.
In those areas of the country where microbial contamination exists because of careless fuel handling, it is recommended that microbial contamination be
controlled by use of the above product or its equivalent. Do not exceed the dosage recommended on the label. The dosage recommended is sufficient.
Whenever continuously towing a trailer, discontinue the use of BIOBOR(R) Diesel Doctor. Resume dosage when trailer towing has ended. Chevrolet
uses BIOBOR(R) in the factory fill so that treatment of that fuel is not necessary.
It is recommended that you take advantage of the introduction of this product to remind your customers of the potential for microbial contamination of
diesel fuels. Treatment of diesel fuel to prevent this condition is preferable to correcting the damage once it occurs. If microbial contamination is
identified in a fuel system, the fuel tank should be cleaned. Steam cleaning may be necessary only if you are unable to remove most of the microbial
growth. The biocide will kill the growth, and in extremely contaminated tanks, the residue could float free and plug the filter if the excess debris is not
removed.
Care should be exercised when working with these microorganisms to keep them out of open sores on the skin.
One source for BIOBOR Diesel Doctor is KREX, Inc. For convenience, a copy of their order form is attached.
