Chevrolet Low Cab Forward 2016 Manual page 260

1. When the engine is cool,
remove the radiator cap (1).
Turn the cap slowly to the
left until it reaches a stop .
Do not press down while
turning the cap.
Wait until any remaining
pressure (indicated by a
hissing sound) is relieved,
then press down on the cap
and continue turning it to
the left.
2. Fill the radiator to the base of
the filler neck (2).
Add enough engine coolant
to provide the required
cooling, freezing and
corrosion protection.
Install the radiator cap.
3. Run the engine until the engine
coolant temperature rises to
normal level, and idle the
engine for 10 minutes.
4. Turn off the engine. Make sure
that the engine is cool.
Remove the radiator cap and
add engine coolant to the
radiator until it reaches the
base of the filler neck.
5. Install the radiator cap.
Check, replenish or change the
engine coolant only after the engine
has sufficiently cooled down.
When the engine is still hot, take
care to prevent engine coolant from
contact with the exhaust manifold.
Any such contact could result in
exhaust manifold damage.
Vehicle Care
If you use the proper quality engine
coolant, there is no need to add
extra inhibitors or additives which
claim to improve the system. They
may be harmful to the proper
operation of the system.
Do not overfill the engine coolant
reserve tank.
If the level of engine coolant
changes rapidly, have your vehicle
inspected at your dealer.
Thermostat
The engine coolant temperature is
controlled by thermostat(s). The
thermostats stop engine coolant
flow through the radiator until a
preset temperature is reached. The
thermostats are installed in the
engine coolant outlet on the engine
block. The same thermostats are
used in both winter and summer.
When a replacement is needed,
genuine GM parts are
recommended.
259