Paccar PX 8, Operator'S Manual

Page: 73 / 94

Maintenance Specifications
PACCAR Y53-1030A 12/09
– 67 –
Good-quality water is important for cooling system perfor-
mance. Excessive levels of calcium and magnesium contrib-
ute to scaling problems, and excessive levels of chlorides
and sulfates cause cooling system corrosion.
Fully formulated antifreeze must be mixed with good quality
water at a 50/50 ratio (40- to 60-percent working range). A
50/50 mixture of antifreeze and water gives a -36°C [-33°F]
freezing point and a 108°C [226°F] boiling point, which is
adequate for locations in North America. The actual lowest
freezing point of ethylene glycol antifreeze is at 68 percent.
Using higher concentrations of antifreeze will raise the freez-
ing point of the solution and increase the possibility of a silica
gel problem.
PACCAR vehicle engine-cooling systems are filled with fully
formulated extended-life coolant (ELC).
PACCAR recommends the use of fully formulated extended
life coolant that meets the requirements of Cummins Engi-
neering Standard (C.E. S.) 14603 for top off and service.
If the replacement coolant is Chevron Texaco, Shell Rotella
or their private label counterparts which do not meet the elas-
tomer compatibility section of CES 14603, the coolant must
be treated by adding 0.24 liter (8oz) of liquid silicate fluid for
every 45 liters (12 gal) of total coolant system volume. It is
critical to not over treat the coolant with silicate fluid. If over-
treatment is suspected, drain the cooling system and discard
the filter. Clean the cooling system immediately. Symptoms
of silicate over-treatment can be thickened coolant in the
lower radiator tank, water pump seal leakage soon after sili-
cate addition, reduced heater output and/or elevated engine
temperatures.
To obtain order forms or ask questions relative to ordering
the silicate fluid, contact:
Silicate Fluid Order Program
P.O. Box 27388
Houston, TX 77277-7388
Phone: 800-346-9041
Fax: 800-876-5317
Water Quality
Calcuim Magnesium
(hardness)
Maximum 170 ppm as
(CaCO
3
+ MgCO
3
)
Chloride 40 ppm as (Cl)
Sulfur 100 ppm as (SO
4
)