2009 Chevrolet Suburban Owner's Manual - Page 438

If the vehicle has electric cooling fans, you may hear the fans spinning at low speed during most everyday driving. The fans may turn off if no cooling is required. Under heavy vehicle loading, trailer towing, and/or high outside temperatures, or if you are operating the air conditioning system, the fans may change to high speed and you may hear an increase in fan noise. This is normal and indicates that the cooling system is functioning properly. The fans will change to low speed when additional cooling is no longer required. When to Check Power Steering Fluid It is not necessary to regularly check power steering fluid unless you suspect there is a leak in the system or you hear an unusual noise. A fluid loss in this system could indicate a problem. Have the system inspected and repaired. How to Check Power Steering Fluid To check the power steering fluid: 1. Turn the key off and let the engine compartment cool down. 2. Wipe the cap and the top of the reservoir clean. 3. Unscrew the cap and wipe the dipstick with a clean rag. 4. Replace the cap and completely tighten it. 5. Remove the cap again and look at the fluid level on the dipstick. The level should be at the FULL COLD mark. If necessary, add only enough fluid to bring the level up to the mark. Power Steering Fluid If the vehicle is a Two-mode Hybrid, see the Two-mode Hybrid manual for more information. See Engine Compartment Overview on page 5-14 for reservoir location. 5-38