For 1990-2009 cars

† The U.S. Environmental Protection Agency or the California Air Resources Board has determined that the failure to perform this maintenance item will not nullify the emission warranty or limit recall liability prior to the completion of the vehicle's useful life. We, however, urge that all recommended maintenance services be performed at the indicated intervals and the maintenance be recorded.

# Lubricate the front suspension, ball joints, steering linkage, underbody contact points and linkage (Uplander and Montana SV6), and parking brake cable guides. Control arm ball joints on Escalade, EXT, Avalanche, Sierra Denali, Yukon Denali, 1500 series Silverado/Sierra, and 1500 series Tahoe/Yukon vehicles are maintenance-free. On other vehicles, control arm ball joints require lubrication but should not be lubricated unless their temperature is 10°F (-12°C) or higher, or they could be damaged. Silverado/Sierra vehicles used under severe commercial operating conditions require lubrication on a regular basis every 3,000 miles (5 000 km).

(a) Visually inspect brake lines and hoses for proper hook-up, binding, leaks, cracks, chafing, etc. Inspect disc brake pads for wear and rotors for surface condition. Inspect other brake parts, including calipers, parking brake, etc. For vehicles with rear drum brakes: Inspect brake linings/shoes for wear or cracks, brake drums, wheel cylinders, etc.

(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" and "Windshield Wiper Blades" in your owner manual 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" in your owner manual .

(f) Lubricate all key lock cylinders, hood latch assembly, secondary latch, pivots, spring anchor, release pawl, rear compartment hinges, any gate handle pivot points, rear door detent link, roller mechanism, latch bolt, fuel door hinge, any cargo 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) Check vent hose at transfer case for kinks and proper installation.

(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.

• | Silverado/Sierra vehicle GVWR is over 8600 lbs.

(i) Drain, flush, and refill cooling system. This service can be complex; you should have your dealer/retailer perform this service. See Recommended Fluids and Lubricants 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 you drive regularly under dusty conditions, inspect the filter at each engine oil change.

(m) If you drive regularly under dusty conditions, the filter might require replacement more often.

(n) 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.

(o) Visually inspect belt for fraying, excessive cracks, or obvious damage. Replace belt if necessary.

(p) Extreme Duty Service: Change transfer case fluid if the vehicle is mainly driven off-road in four-wheel drive, or is used for heavy trailer towing. Farming, mining, forestry, and Department of Natural Resources (DNR) vehicles meet this definition.

(q) 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.