Cooling System; Closed Heat Exchanger; Checking And Filling Coolant; Flushing And Cleaning - Kohler 4EFOZ Operation Manual

3.8 Cooling System

3.8.1

Closed Heat Exchanger

In a closed cooling system, the seawater circulates
through separate chambers within the heat exchanger or
manifold to cool the engine water. The seawater then
mixes with the engine exhaust and ejects out of the
exhaust outlet. See Figure 3-6 for coolant capacities
(include coolant recovery tank capacity of 0.24 L (8 oz.).
Model
4EFOZ and 5EOZ
6.5EFOZ and 8EOZ
8.5EFOZ, 9EFOZ and 10EOZ
11/11.5/13EFOZ and 13/14/15.5EOZ
16/17.5/19/20EFOZ and 20/23/24EOZ
23/27EFOZ and 28/32EOZ
Figure 3-6 Coolant Capacities
3.8.2

Checking and Filling Coolant

WARNING
Hot coolant and steam.
Can cause severe injury or death.
Before removing the pressure cap,
stop the generator set and allow it to
cool. Then loosen the pressure cap
to relieve pressure.
Checking the coolant level. Hot coolant can cause severe
injury or death. Allow the engine to cool. Release pressure
from the cooling system before removing the pressure cap. To
release pressure, cover the pressure cap with a thick cloth and
then slowly turn the cap counterclockwise to the first stop.
Remove the cap after pressure has been completely released
and the engine has cooled. Check the coolant level at the tank
if the generator set has a coolant recovery tank.
NOTICE
Saltwater damage. Saltwater quickly deteriorates metals.
Wipe up saltwater on and around the generator set and
remove salt deposits from metal surfaces.
Maintain the coolant level in the coolant recovery tank at
approximately 1/4 full. Before filling the cooling system,
close all petcocks and tighten all hose clamps. Use a
solution of 50% ethylene glycol and 50% clean,
softened water to inhibit rust/corrosion and prevent
freezing. Add additional coolant solution, as necessary,
to the coolant recovery tank. Periodically check the
18 Section 3 Scheduled Maintenance
coolant level on closed systems by removing the
pressure cap. Do not rely solely on the level in the
coolant recovery tank. Add fresh coolant until the level is
just below the overflow tube opening.
Note: A coolant solution of 50% ethylene glycol
provides freezing protection to --37°C (--34°F)
and overheating protection to 129°C (265°F). A
coolant solution with less than 50% ethylene
glycol may not provide adequate freezing and
overheating protection. A coolant solution with
more than 50% ethylene glycol can cause engine
L (Qts.)
or component damage. Do not use alcohol or
1.8 (1.9)
methanol antifreeze or mix them with the
3.9 (4.1)
specified
manufacturer's operation manual for engine
2.5 (2.6)
coolant specifications.
4.4 (4.6)
6.0 (6.3)
Note: Do not add coolant to a hot engine. Adding
7.6 (8.0)
coolant to a hot engine can cause the cylinder
block or cylinder head to crack. Wait until the
engine has cooled.
Note: Pay special attention to the coolant level. After
the coolant drains, allow time when re-filling the
coolant for a complete refill of the engine water
jacket. Check the coolant level as prescribed in
the Prestart Checklist.
3.8.3
For optimum protection, drain, flush, and refill the
cooling system at the interval listed in the service
schedule.
Flushing and Cleaning Procedure
1. Open the pressure cap and open petcocks located
at the heat exchanger, engine block, and cooling
system, and let the system drain completely. Some
models may have petcocks located behind the belt
guard.
draining.
2. Drain, clean, and flush the coolant recovery tank.
3. Flush the system with clean water.
4. Fill the system with recommended coolant.
3.8.4
Closed heat exchanger systems utilize a pressure cap
to raise the boiling point of the coolant, enabling higher
operating temperatures. If the cap leaks, replace it with
a cap of the same rating. The pressure cap typically has
the pressure rating stamped on the cap body.
coolant. Consult

Flushing and Cleaning

Remove the pressure cap to simplify

Pressure Cap

the engine
TP-6068 10/02