SERIES 50 OPERATOR'S GUIDE
Coolant Extender Inhibitor
Additive for “OAT” Coolant
The inhibitors in OAT coolant must
also be maintained, but less often
than traditional SCA-type coolants.
A portable test is available to test the
levels of OAT inhibitors in coolant.
Where this is not used, fleet testing
has determined that a OAT coolant
extender package should be added to
the coolant at 300,000 miles (480,000
km), two (2) years, or 5,000 hours,
whichever comes first. The proper
maintenance dosages for all OAT
coolants are listed in Table 26 ,
reflecting 0.6% by volume extender.
This dosage should be added to the
water-only and the glycol systems at
the same interval.
The proper application of extender to
OAT coolant will provide:
pH Control
Restored inhibitor levels to
prevent corrosion
Cavitation protection to protect
wet sleeve cylinder liners
NOTE:
Do not use traditional SCAs in
OAT coolant, and do not use
OAT extender in traditional coolant.
OAT Coolant Drain Interval —
A
properly maintained OAT-inhibited
coolant will last 600,000 miles
(960,000 km), four (4) years, or
10,000 operating hours, whichever
comes first. At this time the coolant
should be drained, and the cooling
system should be thoroughly cleaned,
flushed, and filled with new, properly
inhibited OAT coolant.
Chronic Coolant System
Problems
The most commonly seen coolant
system problems result from
maintenance and formulation factors
such as:
Hard water
Dilution of the coolant by the
addition of untreated water
Over dosage or under dosage of
corrosion inhibitors
Improper corrosion inhibitor
(most often phosphated)
Mixing SCAs
Improper testing
Detroit Diesel Cooling System
Maintenance Products
Power Cool
SCAs —
Power Cool
SCAs are water-soluble chemical
compounds. These products are
available in coolant filter elements,
All information subject to change without notice.
(Rev. 01/ 04)
109
6SE550 0401
Copyright © 2004 DETROIT DIESEL CORPORATION
