PRODUCT INFORMATION
INDEX
DATE
Dep. 2
IO-C-M-20-002e G
June 2016
COOLING SYSTEM MAINTENANCE
3/5
There are two ways to
fill the circuit
:
1. Fill with water previously mixed with antifreeze.
This is the best system to use for filling the cooling
circuits. Water with antifreeze in the right proportion is premixed in a tank (
refer to IP IO-CM-20-001
), so
what we feed into the engine is a homogeneous mixture of water and glycol. Filling is done using an electric
pump or by gravity until the right pressure is achieved.
2. Fill with water and subsequently add antifreeze
. This method is not recommended because the mixture
will not be homogeneous until the water pumps are started, which if after adding antifreeze we do not
operate the pumps at specific points in the circuit, we only have water that can freeze after a certain period
of time. Therefore, when filling it is important to make sure that after starting the engine, we reach a sufficient
load to open the thermostats and recirculate water and antifreeze around the circuit, such that after stopping
the circuit, it is full and there is no risk of freezing.
In both cases ensure that the ratio of water to antifreeze is correct
(refer to IP IO-C-M-20-001).
A
hydrometer
is
used to determine the concentration of glycol in the water, which will give the density of the water/antifreeze
mixture. The supplier of the antifreeze is required to provide the table that correlates density and concentration.
A
refractometer
can also be used to get an immediate reading for the concentration value. IP IO-C-M-20-001
displays a graph indicating, based on the concentration and, if the antifreeze is ethylene glycol or propylene
glycol, the temperature at which the mixture freezes, in addition to the recommendations on the additive to be
used.
The air bleed valves must be opened until no further air bleeds out. For closed, pressurized circuits, the circuit is
filled to a pressure slightly above 1 bar.
Fig. 5 - Typical hose/circuit connection for filling and draining the cooling system
During the first engine start-up and when the water is a little hot again, open the purge valves to ensure only
water flows out. If air comes out, leave them open until the air is completely released. If the pressure in the
circuit has lowered a lot, it has to be filled up sufficiently.
It is very important to ensure that there is no air in the circuit, since this greatly reduces the cooling capacity,
causing explosions in the cylinders, cavitation in the water pumps and a considerable decrease in the flow of
water that is circulating through the engine circuits.
5.2.57
O&M_2.002211.810_A_10_2016
