C O O L I N G
S Y S T E M
T E S T I N G
A N D
A D J U S T I N G
Testing Radiator and Cooling System for
To test the radiator and cooling system for leaks,
use the procedure that follows:
Always stop the engine to inspect the cooling
system. Loosen the pressure cap to the first
stop and let the pressure out of the cooling
system, then remove the pressure cap. Hot
coolant and steam can cause personal injury.
Let coolant become cool before it is drained.
Remove the filler cap from the radiator.
Make sure the coolant is over the top of the
3. Put the 9S8140 Cooling System Pressurizing
Pump Group on the radiator.
Get the pressure reading on the gauge to
20 kPa (3 psi) more than the pressure of the
Check the radiator for outside leakage.
Check all connections and hoses for the cooling
system for outside leakage.
If you do not see any outside leakage and the
pressure reading on the gauge is still the same
after 5 minutes, the radiator and cooling system
does not have leakage. If the reading on the
gauge goes down and you do not see any outside
leakage, there is leakage on the inside of the
cooling system. Make repairs as necessary.
Water Temperature Regulator
1. Remove the regulator from the engine.
2. Heat water in a pan until the temperature is
90°C (195°F). This is the correct temperature
for opening the regulator. Move the water
around in the pan to make it all be the same
3. Hang the regulator in the pan of water. The
regulator must be below the surface of the water
and it must be away from the sides and bottom of
4. Keep the water at the correct temperature for 10
5. After ten minutes, remove the regulator and
immediately measure the distance the regulator
has opened. The distance must be a minimum of
9.53 mm (.375 in.).
6. If the distance is less than 9.53 mm (.375 in.),
make a replacement of the regulator.