Cadillac 2009 STS, Owner'S Manual

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(i) If using DOT-4 brake fluid only: Drain, flush, and refill
brake hydraulic system at a regular maintenance service
every two years. This service can be complex; you should
have your dealer/retailer perform this service. See Brakes
on page 5-39.
(j) Drain, flush, and refill cooling system. This service can
be complex; you should have your dealer/retailer perform
this service. 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.
(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.
(l) Drain, flush, and refill intercooler system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-27.
(m) If driving regularly under dusty conditions, inspect
the filter at each engine oil change.
(n) Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
(p) If the vehicle has the 3.6L V6 (VIN Code V) engine,
replace the engine air cleaner filter every 40,000 miles
(64 000 km).
(q) Check vent hose at transfer case for kinks and proper
installation. Check to be sure vent hose is unobstructed,
clear, and free of debris. During any maintenance, if a
power washer is used to clean mud and dirt from the
underbody, care should be taken to not directly spray the
transfer case output seals. High pressure water can
overcome the seals and contaminate the transfer case
fluid. Contaminated fluid will decrease the life of the
transfer case and should be replaced.
(r) Change transfer case fluid 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 or taxi,
police, or delivery service.
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