GMC 1994 Yukon Owner's Manual page 222

6.
Start the engine
and let it run until
you can feel the
upper radiator
hose getting hot.
Watch out for the
engine fan( s).
7. By this time the coolant level inside the radiator filler neck may be
lower. If the level is lower, add more of the proper mix through the
filler neck until the level reaches the base of the filler neck.
Cooling System -Diesel Engines
When you decide it's
safe to lift the hood,
here's what you'll see:
A. Coolant surge
tank pressure cap
..$.?A.
.
."
_ . .
8.
Then replace the
pressure cap. At
any time during
this procedure if
coolant begins to
flow out of the
filler neck,
reinstall the
pressure cap. Be
sure the arrows
on pressure cap
line up like this.
B
.
Engine fan( s)
C. Radiator
5-18