Cooling System - Inspect; Cooling System - Cooling System - T T Est Est - Perkins 1103 Series Workshop Manual

13. When a load that is applied to the engine is too
large, the engine rpm does not increase with an
increase of fuel. This lower engine rpm causes
a reduction in coolant flow through the system.
This combination of less air and less coolant flow
during high input of fuel will cause above normal
heating.

Cooling System - Inspect

This engine has a pressure type cooling system. A
pressure type cooling system gives two advantages:
•
The pressure type cooling system can operate
safely at a higher temperature than the boiling
point of water at a range of atmospheric
pressures.
• The pressure type cooling system prevents
cavitation in the water pump.
Cavitation is the sudden generation of low pressure
bubbles in liquids by mechanical forces. The
generation of an air or steam pocket is much more
difficult in a pressure type cooling system.
Regular inspections of the cooling system should be
made in order to identify problems before damage
can occur. Visually inspect the cooling system
before tests are made with the test equipment.
Visual Inspection Of The Cooling
System
1. Check the coolant level in the cooling system.
2. Look for leaks in the system.
3. Inspect the radiator for bent fins and other
restriction to the flow of air through the radiator.
4. Inspect the drive belt for the fan.
5. Inspect the blades of the fan for damage.
6. Look for air or combustion gas in the cooling
system.
7. Inspect the radiator cap for damage. The sealing
surface must be clean.
8. Look for large amounts of dirt in the radiator core.
Look for large amounts of dirt on the engine.
9. Shrouds that are loose or missing cause poor
air flow for cooling.
Cooling System - Test
Remember that temperature and pressure work
together. When a diagnosis is made of a cooling
system problem, temperature and pressure must
be checked. The cooling system pressure will have
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an effect on the cooling system temperature. For
an example, refer to Illustration 34. This will show
the effect of pressure on the boiling point (steam)
of water. This will also show the effect of height
above sea level.
Illustration 34
Cooling system pressure at specific altitudes and boiling points
of water
Personal injury can result from hot coolant, steam
and alkali.
At operating temperature, engine coolant is hot
and under pressure. The radiator and all lines
to heaters or the engine contain hot coolant or
steam. Any contact can cause severe burns.
Remove filler cap slowly to relieve pressure only
when engine is stopped and radiator cap is cool
enough to touch with your bare hand.
The coolant level must be to the correct level in
order to check the coolant system. The engine must
be cold and the engine must not be running.
After the engine is cool, loosen the pressure cap
in order to relieve the pressure out of the cooling
system. Then remove the pressure cap.
The level of the coolant should not be more than
13 mm (0.5 inch) from the bottom of the filler pipe.
If the cooling system is equipped with a sight glass,
the coolant should be to the correct level in the
sight glass.
Testing and Adjusting Section
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