operators_manual

CAUTION
Use of non-genuine PACCAR coolant
filters can cause severe engine dam-
age.
Concentration
Check the level of freeze/boil-over
protection, which is determined by the
glycol concentration. Use a glycol
refractometer to determine glycol level.
Add coolant to obtain the coolant/water
ratio required to provide the protection you
need. A 50:50 mix of coolant and water is
adequate for most applications. For
extremely cold operating conditions, the
ratio can be adjusted to a higher
concentration of coolant.
NOTE
Maximum recommended ELC concen-
tration is 60% ELC and 40% water by
volume (a 60:40 coolant mixture). The
minimum recommended concentration
is 40%.
Glycol Concentration Level
Level
Desired
Coolant
/ Water
Ratio
Freeze
Point °F
(°C)
Recommended
Levels
40% -12 (-24)
45% -23 (-31)
50% -34 (-37)
55% -50 (-46)
60% -62 (-52)
Condition
Perform a visual inspection of the coolant.
It should have no cloudiness or floating
debris. Determine the chemical inhibitor
concentration level by using an extended
life coolant specific test kit or test strips.
Inhibitor concentration level determines
corrosion protection. If you are concerned
about possible coolant quality,
contamination, or mechanical problems,
submit a coolant sample for analysis.
Improper maintenance may cause coolant
degradation and could result in damage to
the cooling system and engine
components. Consult your dealer or
the coolant manufacturer’s representative
for recommended extended life coolant test
kits, test strips, and laboratory sample
procedures.
Coolant Extender
Add extended life coolant extender, if
necessary, according to the corrosion
inhibitor concentration required. DO NOT
add coolant extender to nitrite-free coolant.
Checking Coolant Level
Check the coolant level daily. When adding
coolant, avoid mixing different brands and
formulations. If the coolant is mixed with
more than 25% of a different formulation,
engine corrosion damage could occur. If
mixing exceeds 25% of total system
volume, it is recommended to flush and
refill the system completely with one type
of coolant.
Coolant Filter
Your engine may be equipped with a
coolant filter. It is a "blank filter" and does
not contain chemicals or time-release
additives. Replace it only with a blank filter
at the interval specified in your engine's
MAINTENANCE - Cooling System Maintenance
Y53-6126-1A1 (01/21) 251
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