Chevrolet EXPRESS - 2011 Manual page 284

Because this operation can be a
little difficult, it may be decided
to have this done at the dealer
service department.
If not taken to the dealer, be sure
to follow all the instructions here
or a false reading on the dipstick
could result.
Wait at least 30 minutes before
checking the transmission fluid level
if you have been driving:
When outside temperatures are
above 32°C (90°F).
At high speed for quite a while.
In heavy traffic especially in
hot weather.
While pulling a trailer.
To get the right reading, the fluid
should be at normal operating
temperature, which is 82°C to 93°C
(180°F to 200°F).
Get the vehicle warmed up by
driving about 24 km (15 mi) when
outside temperatures are above
10°C (50°F). If it is colder than 10°C
(50°F), drive the vehicle in 3 (Third)
until the engine temperature gauge
moves and then remains steady for
10 minutes.
A cold fluid check can be made
after the vehicle has been sitting
for eight hours or more with the
engine off, but this is used only
as a reference.
Let the engine run at idle for
five minutes if outside temperatures
are 10°C (50°F) or more. If it is
colder than 10°C (50°F), the engine
may have to idle longer. Should the
fluid level be low during this cold
check, the fluid must be checked
hot before adding fluid. Checking
the fluid hot will give a more
accurate reading of the fluid level.
Prepare the vehicle as follows:
1. Park the vehicle on a level
place. Keep the engine running.
2. With the parking brake applied,
place the shift lever in P (Park).
3. With your foot on the brake
pedal, move the shift lever
through each gear range,
pausing for about three seconds
in each range. Then, position the
shift lever in P (Park).
4. Let the engine run at idle for
three minutes or more.