VISUAL INSPECTION OF THE COOLING SYSTEM

COOLING SYSTEM

TESTING AND ADJUSTING

COOLING SYSTEM

The cooling system is a pressure type with regulators

system problem, temperature and pressure must both be

at the outlet, the cooling system is equipped with a shunt

checked. Cooling system pressure will have an effect on

line.

cooling system temperatures. For an example, look at the

chart to see the effect of pressure and height above sea

A pressure type cooling system gives two

level on the boiling (steam) point of water.

advantages. The first advantage is that the cooling

system can have safe operation at a temperature that is

Test Tools for Cooling System

higher than the normal boiling (steam) point of water. The

second advantage is that this type system prevents

Tools Needed: 9S9102 Thermistor Thermometer

cavitation (the sudden making of low pressure bubbles in

Group.

liquids by mechanical forces) in the water pump. With this

9S7373 Air Meter Group.

type system, it is more difficult for an air or steam pocket

1P5500 Portable Phototach Group.

to be made in the cooling system.

9S8140 Cooling System Pressurizing

Pump Group.

The cause for an engine getting too hot is generally

because regular inspections of the cooling system were

The 9S9102 Thermistor Thermometer Group is used

not made. Make a visual inspection of the cooling system

in the diagnosis of overheating (engine running too hot) or

before testing with testing equipment.

overcooling (engine runs too cool) problems. This group

can be used to check temperatures in several different

VISUAL INSPECTION OF THE COOLING SYSTEM

parts of the cooling system. The testing procedure is in

Special Instruction (GMG00450).

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

3. Look for bent radiator fins. Be sure that air flow

through the radiator does not have a restriction.

4. Inspect the drive belt for the fan.

5. Check for damage to the fan blades.

6. Look for air or combustion gas in the cooling

system.

7. Inspect the pressure cap and the sealing surface

for the cap. The sealing surface must be clean.

9S9102 THERMISTOR THERMOMETER GROUP

TESTING THE COOLING SYSTEM

The 9S7373 Air Meter Group is used to check the air

flow through the radiator core. The testing procedure is in

Remember that temperature and pressure work

Special Instruction (GMG00203).

together. When making a diagnosis of a cooling

9S7373 AIR METER GROUP