1996 GMC Savana Van Owner's Manual - Page 184

Driving On Grades Reduce speed and shift to a:lower gear before you start down a long or steep doyngrade. If you don't shift down, you might have to use your brakes so much that they would get hot and no longer work well. On a long uphill grade, shift down and reduce your speed to around 45 mph (70 km/h) to reduce the possibility of engine and transmission overheating. When towingat high altitude on steep uphill grades, consider the following:Engine coolant will boilat a lower temperature thanat normal altitudes. If you turn your engine off immediately after towing at high altitude on steep uphill grades,your vehicle may show signs To similar to engine overheating. avoid this, let the engine run whileparked (preferably on level ground) with the automatic transmission PARK (P) for a few in minutes before turning the engine off.. Ifyou do get the overheat warning, see"Engine Overheating" in the Index. Parking on.Hills You really should not park your vehicle, with a trailer attached, .on a hill. If something goes wrong, your rig could start to move. People can be injured, and both your vehicle and the trailer can be damaged. But if you ever have to park your rig on a hill, here's how to do it: 1. Apply your regular brakes, but don't shift into PARK (P) yet. Then turn your wheels into the curb if facing downhill or into traffic if facing ,uphill. 2. Have someone place chocks under the trailer wheels. 3. When the wheel chocks are in place, release the regular brakes until the chocks absorb the load. 4. Re-apply the regular brakes. Then apply your parking brake and then shift to PARK (P). 5. Release the regular brakes.