Fuel, Oil and Coolant Specifications
use in Detroit Diesel engines. These systems can be used
w i t h either water or permanent type antifreeze
solutions and provide corrosion protection, pH control
and water softening. Some non-chromate inhibitor
systems offer the additional advantage of a simple on
site test to determine protection level and. since they
are added directly to the coolant. require no additional
hardware or plumbing.
When freeze protection is required, a permanent type
a n t i f r e e z e must 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 (Fig. 4).
Methoxy propanol base antifreeze is not recommended
for use in Detroit Diesel engines due to the presence
of fluoroelastomer (Viton `0') seals in the cooling
system. Before installing ethylene glycol base anti-
freeze in an engine previously operated with methoxy
propanol. the entire cooling system should be drained.
flushed with clean water and examined for rust. scale.
system must be chemically cleaned with a commercial
grade heavy-duty de-scaler.
Ethylene glycol base antifreeze is recommended for
use in Series 71 Detroit Diesel engines. Methyl alcohol
antifreeze is not recommended because of its effect on
the non-metallic components of the cooling system
and because of its low boiling point.
The inhibitors in permanent type antifreeze should be
replenished at approximately 500 hour or 20,000 mile
i n t e r v a l s with a non-chromate inhibitor system.
Commercially available inhibitor systems may be used
to re-inhibit antifreeze solutions.
Fig. 4 - Coolant Freezing and Boiling
Temperatures Vs Antifreeze Concentration (Sea
that filler caps and pressure relief mechanisms be
Several brands of permanent antifreeze are available
correctly installed at all times and that coolant levels
with sealer additives. The specific type of sealer varies
be properly maintained.
with the manufacturer. Antifreeze with sealer
additives is not recommended for use in Detroit Diesel
WARNING: Use extreme care when removing a
engines due to possible plugging throughout various
radiator pressure control cap from an engine.
areas of the cooling system.
The sudden release of pressure from a heated
cooling system can result in a loss of coolant
and possible personal injury (scalding) from the
All Detroit Diesel engines incorporate pressurized
cooling systems which normally operate at tempera-
1. Always use a properly inhibited coolant.
tures higher than non-pressurized systems. It is
essential that these systems be kept clean and leakfree,
2. Do not use soluble oil.