Industrial 1.6L Engine Cooling 2-19
Description and Operation
Cooling System Description
Cooling System
This equipment has a pressure-type engine cooling
system. The system has thermostatic control of the
coolant circulation. The cooling system is sealed by a
pressure type radiator cap. The cap causes the system
to operate at a pressure higher than atmospheric
pressure. The high-pressure operation raises the boiling
point of the coolant, which increases the cooling
efficiency of the radiator. The 104 kPa (15 psi) pressure
cap raises the boiling point of the coolant to about
125°C (257°F) at sea level.
Engine Coolant
Always fill the system with ethylene glycol based
coolant to the radiator. Do not pre–mix the coolant and
water. Fill the remainder of the radiator with clean
drinkable water in order to equal a 52/48 mix. Refer to
the mixture chart on the container for additional anti-
freeze protection information. DO NOT use alcohol or
methanol based antifreeze, or mix them with the
specified coolant.
Notice: Antifreeze can be added to raise the
boiling point of the coolant, but too much will
affect the freezing point. Do not use a solution
stronger than 60 percent glycol, 40 percent
water as the freeze level rises rapidly after this
point. Pure antifreeze will freeze at *22°C
(*8°F).
* Approximate values.
Uncommon Cooling System Problems
The following problems do not require disassembly of
the cooling system:
• Large obstructions block the radiator.
• Ice, mud or snow obstructs the radiator
• The engine oil is overfilled.
• Incorrect ignition timing
The following problems do require disassembly of the
cooling system:
• An incorrect or damaged fan
• Incorrect radiator for the application
• Incorrect or faulty radiator pressure cap
• Check the specifications for the correct part
numbers.
• Pressure check the cooling system while the
pressure cap is installed. This shows if the
pressure cap leaks due to radiator filler neck
damage.
• Worn or damaged water pump
- The impeller vanes are eroded or broken.
- The bearing or the seal is worn or damaged.
Check the shaft for bearing play.
• Plugged radiator tubes. Perform a flow check.
• Internal system leaks.
- The cylinder head gasket
- The cracked block
- The timing chain cover
- The intake manifold gasket
• Plugged coolant passages in the cylinder heads. Do a
visual check.
Radiator Assembly Description
The radiator assembly is a downflow tube type utilizing
an aluminum core with brass upper and lower tanks.
It is fitted with a shroud designed to assist the cooling fan
in directing airflow through the radiator cores and also
serves as a fan guard.
An additional fan guard is also installed to protect person-
nel from injury.
Pressure is maintained in the system by a pressure cap.
The pressure cap has two valves: one which relieves
pressure, and the other to compensate for coolant
contraction when the engine is off. The radiator cap on
this system has a 48kPa (7 psi) rating.
Radiator Maintenance
Radiators need special attention to prevent leakage and
airflow restrictions. Check the outside of the radiator for
bent fins or leakage. Leaking radiator cores should be
repaired immediately, not just sealed temporarily with a
sealer-type antifreeze or coolant additive.
Remove the radiator cap and look for plugging and scale
on the inside of the tank. A badly plugged radiator may
have to be replaced. If scale is found, remove it. Refer to
Cooling System Scale Removal.
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