GMC 2003 GMT560 T-Series, Owner'S Manual

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Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice: Your vehicle doesn’t need an elaborate
″
break-in.
″
But it will perform better in the long run
if you follow these guidelines:
•
Let your engine warm up before you operate
your vehicle under load.
•
Keep your speed at 55 mph (88 km/h) or less for
the first 500 miles (805 km).
•
Don’t drive at any one speed — fast or
slow — for the first 500 miles (805 km). Don’t
make full-throttle starts.
•
Avoid making hard stops for the first 200 miles
(322 km) or so. During this time your new
brake linings aren’t yet broken in. Hard stops
with new linings can mean premature wear and
earlier replacement. Follow this breaking-in
guideline every time you get new brake linings.
•
Use the lowest gear you can when you start a
loaded vehicle in motion and when going up
hills to avoid overloading the engine.
•
Check and adjust engine and transmission fluid
levels often and be sure tires are properly
inflated for the load you’re carrying.
•
If you have a Caterpillar
®
diesel engine, see the
Caterpillar
®
Diesel Engine Operation and
Maintenance Manual.
Ignition Positions
Use your ignition key to
start your vehicle. You can
turn the ignition switch
to four different positions.
LOCK: This position allows you to insert and remove
the ignition key.
ACC (Accessory): This position lets you use
accessories when the engine is off.
ON: This is the position for driving.
START: This position starts your engine.
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