Perkins 1106 Series, User Handbook Manual, Page: 38 / 64

Chapter 5 N40469
Page 28
How to check the specific gravity of the
coolant
For mixtures which contain inhibited ethylene glycol:
1. Operate the engine until it is warm enough to open
the thermostat. Continue to run the engine until
the coolant has circulated the cooling system.
2. Stop the engine.
3. Allow the engine to cool until the temperature of
the coolant is below 60
O
C (140
O
F).
Warning! Do not drain the coolant while the engine
is still hot and the system is under pressure because
dangerous hot coolant can be discharged.
4. Remove the filler cap of the cooling system.
4.
Drain some coolant from the cooling system into
a suitable container.
4.
Use a special coolant hydrometer that will check
the temperature and the specific gravity of the
coolant, follow the manufacturer’s instructions.
Note: If a special coolant hydrometer is not available,
put a hydrometer and a separate thermometer into
the antifreeze mixture and check the readings on both
instruments. Compare the readings with the chart.
7. Adjust the strength of the mixture as necessary.
Note: If it is necessary to fill or replenish the coolant
system in service, mix the coolant to the correct
strength before it is added to the coolant system.
Perkins antifreeze with a concentration of 50% will
give protection against frost to a temperature of -35
O
C
(-31
O
F). It will also give protection against corrosion.
This is especially important when there are aluminium
components in the coolant circuit.
Specific gravity chart
A = Percentage antifreeze by volume
B = Mixture temperature in
O
F
C = Specific gravity
D = Mixture temperature in
O
C