1997 GMC Savana Van Owner's Manual - Page 260

Thermostat Engine coolant temperature is controlled by a thermostat in the engine cooling system. The thermostat stops the flow of coolant through the radiator until coolant the reaches a preset temperature. When you replace your thermostat, an AC@thermostat is recommended. When to Check Power SteeringFluid It is not necessaryto regularly check power steering fluid unless you suspectthere 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 SteeringFluid When the engine compartment is cool, wipe the cap and top of the reservoir clean, then unscrew thecap and wipe the dipstick with a clean rag. Replace thecap and completely tighten it. Then remove the cap again and on look at the fluid level the dipstick. The level should beat the FULL COLD mark. If necessary, addonly enough fluid to bring the levelup to the mark. To prevent brake fluid contamination never check or fill the power steering reservoir with the master cylinder cover off. Power Steering Fluid What to Use To determine what kind of fluid to use, see "Recommended Fluids and Lubricants" in the Index. Always use the proper fluid. Failure to use the proper fluid can cause leaks and damage hoses and seals. 6-26