1993 Buick LeSabre Owner's Manual - Page 248

Thermostat Engine coolant temperature is controlled a thermostat by in the engine coolantsystem. The thermostat stops the flow of coolant through the radiator until the coolant reaches a preset temperature. When you replace your thermostat, an ACS thermostat is recommended. How To Check Power Steering Fluid: Unscrew the cap and wipe the dipstick with a clean rag. Replace the cap and completely tighten it. Then remove the cap again and look at the fluid level on the dipstick. When the engine compartment is hot, the level should be at the "HOT" mark. When the engine compartment is cool, the level should be atthe "FULL COLD" mark. Power Steering Fluid :i What to Add: Refer to the Maintenance Schedule to determine what kind of fluid to use. See "RecommendedFluids and Lubricants" in the Index. When adding power steering fli or making a complete fluid change, always use the proper fluid. Failureto use the proper fluid can cause leaks and damage hoses and seals.