2007 Cadillac STS Owner's Manual - Page 511

(f) Lubricate all key lock cylinders. Lubricate all hinges and latches, including those for the hood, rear compartment, glove box door, and console door. 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) If you drive regularly under dusty conditions, the filter may require replacement more often. (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 limousine service. − Uses such as high performance operation. (i) If using DOT-4 brake fluid only: Drain, flush, and refill brake hydraulic system at a regular maintenance service (I or II) every two years. This service can be complex; you should have your dealer perform this service. See Brakes on page 405. (j) Drain, flush, and refill cooling system. This service can be complex; you should have your dealer perform this service. See Engine Coolant on page 389 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) Inspect throttle body bore and valve plates for deposits. Open the throttle valve and inspect all surfaces. Clean as required. (m) If you drive regularly under dusty conditions, inspect the filter at each engine oil change. 511