2009 GMC Savana Van Owner's 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. 6-9