DETROIT DIESEL 53
Fuel, Oil and Coolant Specifications 13.3
Figure B
captive by the zeolite resin can be released into the
coolant by a regenerative process caused by high
chloride content solutions.
BULK INHIBITOR ADDITIVES:
Commercially
packaged inhibitor systems are available which can be
added directly to the engine coolant or to bulk storage
tanks containing coolant solution. Both chromate and
nonchromate systems are available and care should be
taken regarding inhibitor compatability with other coolant
constituents (Figure B).
A nonchromate inhibitor system is recommended for use
in Detroit Diesel engines. These systems can be used
with either water or ethylene glycol antifreeze solutions
and provide corrosion protection, pH control and water
softening. One of the approved nonchromate inhibitor
systems, Nalcool 2000 offers the additional advantage
of a simple on site test to determine protection level
and, since this product is added directly to the coolant, it
Figure C
requires no additional hardware or plumbing.
manufacturers in their coolant filters. The magnesium
ANTIFREEZE
plate will be attached by solutions which will not be
When freeze protection is required, an ethylene glyco!
detrimental to other metals in the cooling system. The
base permanent antifreeze should be used. An inhibitor
dissolved magnesium will be deposited in the hottest
system is included in this type of antifreeze and no
zones of the engine where heat transfer is most critical
additional inhibitors are required on initial fill if a
(Figure C). The use of aluminum or zinc in preference
minimum antifreeze concentration of 30% by volume is
to magnesium is recommended to eliminate this type of
used. Solutions of less than 30% concentration do not
deposit.
provide sufficient corrosion protection. Concentrations
A high chloride coolant will have a detrimental effect on
over 67% adversely affect freeze protection and heat
the water softening capabilities of systems using ion-
transfer rates (Figure D).
exchange resins.
Accumulations of calcium and
magnesium ions removed from the coolant and held
1972 General Motors Corp.
August, 1972
SEC. 13.3 Page 5
