Chevrolet 2007 Colorado Owner's Manual page 343

Then, follow these steps:
1. Remove the filler plug.
2. Check that the lubricant level is up to the
bottom of the filler plug hole.
3. If the fluid level is good, install the plug
and be sure it is fully seated. If the fluid level
is low, add more fluid as described in the
next steps.
How to Add Fluid
Here is how to add fluid. Refer to the Maintenance
Schedule to determine what kind of fluid to use.
See Recommended Fluids and Lubricants on
page 452.
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only
enough fluid to bring the fluid level up to
the bottom of the filler plug hole.
3. Install the filler plug. Be sure the plug is
fully seated.
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