Preventive Maintenance Engine Cooling System
Medium Duty
(R10/06) Y53-6008 – 145 –
ELC Condition (Contamination and Inhibitor Concentra-
tion)
Perform a visual inspection of the ELC. It should have no
cloudiness or floating debris. Determine the chemical
inhibitor concentration level by using an ELC-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 mainte-
nance may cause coolant degradation and could result in
damage to the cooling system and engine components.
Consult your dealer or the ELC manufacturer’s represen-
tative for recommended ELC test kits, test strips, and lab-
oratory sample procedures.
ELC Extender
Add ELC extender if necessary at the maintenance inter-
val under “Cooling” on page 148.
Topping Off
WARNING! Removing the fill cap on a hot
engine can cause scalding coolant to spray
out and burn you badly. If the engine has been
in operation within the previous 30 minutes,
be very careful in removing the fill cap. Pro-
tect face, hands, and arms against escaping
fluid and steam by covering the cap with a
large, thick rag. Do not try to remove it until
the surge tank cools down if you see any
steam or coolant escaping. In any situation,
remove the cap very slowly and carefully. Be
ready to back off if any steam or coolant
begins to escape.
Desired ELC/
Water ratio:
0% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 100%
Freeze point
°F (°C)
+32
(0)
+25
(-4)
+20
(-7)
+15
(-9)
+10
(-12)
+5
(-15)
-5
(-21)
-12
(-24)
-23
(-31)
-34
(-37)
-50
(-46)
-65
(-54)
-75
(-59)
-84
(-64)
-70
(-57)
-55
(-48)
-43
(-42)
-30
(-34)
-5
(-21)
