Paccar MX-11, Operator'S Manual

Page: 85 / 121

Cooling System
Your engine may be equipped with a
coolant filter designed to capture and
remove harmful deposits from the cooling
system to help prolong system life. Refer to
the Preventative Maintenance Schedule for
the recommended coolant filter change
service interval.
WARNING
Do not remove the surge tank fill cap
on a hot engine. It can cause scalding
coolant to spray out and you could be
burned. If the engine has been operat-
ed within the last 30 minutes, be very
careful in removing the radiator cap.
Protect face, hands, and arms against
escaping fluid and steam by covering
the cap with a large, thick rag. Failure
to comply may result in death, person-
al injury, equipment or property dam-
age
WARNING
Handle coolant and antifreeze careful-
ly. Ethylene glycol antifreeze is poison-
ous. Store in original fluid container
only, and always keep out of the reach
of children. Never remove the filler cap
(vertically mounted) on the surge tank
while the engine is still hot. Wait until
the coolant temperature is below
120°F (50°C). Scalding steam and flu-
id under pressure may escape and
cause serious personal injuries. The
pressure cap (horizontally mounted)
on the surge tank should never be
opened. Failure to comply may result
in death, personal injury, equipment or
property damage.
Coolant/Antifreeze Condition
Perform these maintenance procedures
according to the Preventative Maintenance
Schedule.
NOTE
Test the engine coolant at least twice
per year to determine if the coolant
must be replaced. If it is determined
that the coolant should be replaced,
make sure to flush the coolant system.
Contact a PACCAR® Authorized Re-
pair Location for flushing the coolant
system.
1. Check the following anti-freeze
conditions:
• Coolant level
• Freeze point
• pH level
• Nitrite level
• Carboxylate level
Checking Coolant Condition
To ensure the Extended Life Coolant (ELC)
in your vehicle always provides maximum
protection, perform the following tests:
1. Check the coolant color at every
maintenance interval. It
should have no cloudiness, floating
debris, or oils.
2. Test the freeze point at least twice
a year. A refractometer or test
strips can be used to measure the
protection level.
3. Determine the pH and chemical
inhibitor concentration level by
using an ELC-specific test kit or
test strips.
4. Keep the cooling system full by
topping-up using ELC pre-diluted to
ENGINE MAINTENANCE - Maintenance Procedures
Y53-1166-1M1 (10/2020) 83
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