Cadillac 2004 CTS Owner's Manual page 403

(f) Lubricate all key lock cylinders. Lubricate all body door
hinges. Lubricate all hinges and latches, including those
for the hood, rear compartment, console door and any
folding seat hardware. More frequent lubrication may be
required when exposed to a corrosive environment.
Applying silicone grease on weatherstrips with a clean
cloth will make them last longer, seal better and not stick
or squeak.
(g) If you drive regularly under dusty conditions,
the filter may require replacement more often.
(h) Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
− In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
− In hilly or mountainous terrain.
− When doing frequent trailer towing.
− Uses such as high performance operation.
If you do not use your vehicle under any of these
conditions, the fluid and filter do not require changing.
(i) Drain, flush and refill cooling system. See Engine
Coolant on page 5-27 for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and filler neck.
Pressure test the cooling system and pressure cap.
(j) Replace the belt (or every 96 months, whichever
occurs first). Failure to follow the maintenance described
may result in a broken timing belt and could cause
severe engine damage. It is important to use only
genuine GM parts when replacing the timing belt.
(k) A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired
and the fluid level checked. Add fluid if needed.
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