2008 GMC Sierra 1500 Pickup Owner's Manual - Page 436

(b) Visually inspect front and rear suspension and steering system for damaged, loose, or missing parts, signs of wear, or lack of lubrication. Inspect power steering lines and hoses for proper hook-up, binding, leaks, cracks, chafing, etc. Visually check constant velocity joints, rubber boots, and axle seals for leaks. (c) Visually inspect hoses and have them replaced if they are cracked, swollen, or deteriorated. Inspect all pipes, fittings, and clamps; replace with genuine parts as needed. To help ensure proper operation, a pressure test of the cooling system and pressure cap and cleaning the outside of the radiator and air conditioning condenser is recommended at least once a year. (d) Inspect wiper blades for wear, cracking, or contamination. Clean the windshield and wiper blades, if contaminated. Replace wiper blades that are worn or damaged. See Windshield Wiper Blade Replacement on page 5-57 and Windshield and Wiper Blades on page 5-103 for more information. (e) Make sure the safety belt reminder light and safety belt assemblies are working properly. Look for any other loose or damaged safety belt system parts. If you see anything that might keep a safety belt system from doing its job, have it repaired. Have any torn or frayed safety belts replaced. Also see Checking the Restraint Systems on page 1-70. (f) Lubricate all key lock cylinders, hood latch assembly, secondary latch, pivots, spring anchor, release pawl, door hinges, liftgate hinge, liftgate linkage, liftgate handle pivot points, latch bolt, fuel door hinge, locks, and 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) 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. (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. 6-8