Longlife coolant in older cars

[Hirsch <Catenary@domain.elided>]

Dr. Ted Siverns writes:

>> ...the new longlife coolants (5 years, 160,000 km =3D 100,000
miles) are silicate and phosphate free. They are also aluminum
compatible. A 70-30 mix protects to -64C/-84F and raises the
boiling point to 135C/276F. A 50-50 mix protects to -37C/-34F
and raises the boiling point to 129C/265F -with 15lb pressure cap.
<<

There was an interesting discussion of the use of Texaco's
longlife coolant DEX-COOL in older cars in "Skinned Knuckles"
magazine.

The article is reprinted at the i Saluti website:

   http://www.geocities.com/MotorCity/Downs/3837/dexcool.html

Some excerpts:

"...DEX-COOL is an, excellent product for factory fresh vehicles
that never had traditional phosphate/silicate antifreeze in their
cooling systems. It is also appropriate for use in older vehicles
with completely new cooling system components and which are driven
on a daily basis. Ross identifies some very serious issues with
regard to using DEX-COOL in the treatment of older, antique, or
classic automobiles.

"...in some cooling systems, DEX-COOL may interact with internal
materials. For this reason, a recent service bulletin from GM
specifically states, DEX-COOL may be used in 1994 and later
Buick models for improved water pump seal performance. It should
not be used in 1993 or earlier vehicles because its chemical
ingredients interact with internal copper-soldered joints. =


"...the bottom line is that by using a carboxylate-based antifreeze
such as DEX-COOL in a system that contains residuals from the old
antifreeze, you could actually do more damage than good. Probably
the best approach is to use a traditional antifreeze, the type the
system was designed to use. Then, as discussed in the March article,
add the recommended amount of No-Rosion to extend the interval
between changes and and flushing as well as to ensure protection
while the vehicle sits for extended periods."

Rich Hirsch
'87 Milano
'78 Spider
'67 Duetto
'66 Sprint GTV
Editor, i Saluti, St Louis AROC
Website: http://www.catenary.com/victor/isaluti

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