CHEVROLET 2009 Silverado - Manual (Page 53)

{ CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot enough.
Do not spill coolant on a hot engine.
If the DMCM coolant is empty, the vehicle must be
serviced by your dealer and a special fill procedure must
be followed.
Notice: Attempting to fill the DMCM cooling surge
tank yourself when the fluid level is empty can
damage your vehicle. Your vehicle must be serviced.
1. Park the vehicle on a level surface and turn the
vehicle off. Remove the DMCM coolant surge tank
pressure cap when the DMCM cooling system,
including the DMCM coolant surge tank pressure cap
and DMCM cooling hoses, are no longer hot. Turn
the DMCM coolant surge tank pressure cap slowly
counterclockwise (left) about one full turn. Wait
30 seconds.
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