GMC 2009 Savana - Manual (Page 363)

(g) Vehicles with Gross Vehicle Weight Rating (GVWR)
above 10,000 lbs (4 536 kg) only: Inspect shields for
damage or looseness. Adjust or replace as required.
This is a Noise Emission Control Service. Applicable to
vehicles sold in the United States and recommended
for vehicles sold in Canada.
(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 found in taxi, police, or delivery
service.
(i) 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 5-25 for what to
use. Inspect hoses. Clean radiator, condenser, pressure
cap, and filler neck. Pressure test the cooling system and
pressure cap.
(j) 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.
(k) Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing, and condition. Check
that the purge valve works properly, if equipped.
Replace as needed.
(l) If driving regularly under dusty conditions, inspect the
filter at each engine oil change.
(m) Check system for interference or binding and for
damaged or missing parts. Replace parts as needed.
Replace any components that have high effort or
excessive wear. Do not lubricate accelerator or cruise
control cables.
(n) Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
(o) 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.
(p) Severe Service: Change transfer case fluid if the
vehicle is mainly used for trailer towing or driven in city
traffic, wet environment, or high ambient temperatures.
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