13.3
Fuel, Oil and Coolant Specifications
DETROIT DIESEL 53
A high chloride coolant will have a detrimental effect on the water
softening capabilities of systems using ion-exchange resins.
Accumulations. of calcium and magnesium ions removed from the
coolant and held 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 non-chromate systems are available and care should
be taken regarding inhibitor comparability with other coolant
constituents (Figure B).
A non-chromate inhibitor system is recommended for use in Detroit
Diesel engines. The non-chromate systems can be used with either
water or ethylene glycol antifreeze solutions and provide corrosion
protection, pH control and water softening. Some of the approved
non-chromate inhibitor systems offer the additional advantage of a
simple on site test to determine protection level.
ANTIFREEZE
When freeze protection is required, an ethylene glycol base
Figure C
permanent antifreeze should be used. An inhibitor system is
included in this type of antifreeze and no additional inhibitors are
required on initial fill if a minimum antifreeze concentration of 30%
by volume is used. Solutions of less than 30% concentration do not
provide sufficient corrosion protection.
Concentrations over 67% adversely affect freeze protection and heat
transfer rates (FIGURE D).
Inhibitor depletion will occur in ethylene glycol base antifreeze through
normal service. The inhibitors must be replenished at approximately 500
hour or 20,000 mile intervals with a non-chromate inhibitor system.
Commercially available inhibitor systems (Fig. B) may be used to re-
inhibit antifreeze solutions. Several brands of permanent antifreeze are
available with sealer additives. The specific type of sealers vary with the
manufacturer. Antifreeze with sealer additives is not recommended for
use in Detroit Diesel engines due to plugging problems throughout
various areas of the cooling system.
(Figure D).
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