1999 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 276
1999 Chevrolet Silverado 1500 Pickup Manual
Page 276 highlights
yellowblue 1. You can remove the coolant surge tank pressure cap when the cooling system, including the coolant surge tank pressure cap and upper radiator hose, is no longer hot. Turn the pressure cap slowly counterclockwise (left) about one full turn. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left. 2. Then keep turning the pressure cap slowly, and remove it. 3. Then fill the coolant surge tank with the proper mixture, to the FILL COLD mark. 5-16
yellow
blue
5-16
1.
You can remove the coolant surge tank pressure cap
when the cooling system, including the coolant surge
tank pressure cap and upper radiator hose, is no
longer hot. Turn the pressure cap slowly
counterclockwise (left) about one full turn. If you
hear a hiss, wait for that to stop. A hiss means there
is still some pressure left.
2.
Then keep turning the pressure cap slowly, and
remove it.
3.
Then fill the coolant surge tank with the proper
mixture, to the FILL COLD mark.