GMC 1996 Sierra Owner's Manual page 312

Cleaning the Outside of the
Windshield and Wiper Blades
If the windshield is not clear after using
the
windshield
washer, or if the wiper blade chatters when running, wax
or other material may be on the blade or windshield.
Clean the outside of the windshield with GM Windshield
Cleaner, Bon-Ami Powder@ (GM Part No. 10500 1 I
).
The windshield is clean if beads do not form when you
rinse it with water.
Clean the blade by wiping vigorously with a cloth
soaked in full-strength windshield washer solvent. Then
rinse the blade with water.
Wiper blades should be checked on a regular basis and
replaced when worn.
Weatherstrips
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth at least every six
months. During very cold, damp weather more frequent
application may be required. (See "Recommended
Fluids and Lubricants" in the Index.)
Cleaning the Outside of Your Vehicle
The paint finish on your vehicle provides beauty, depth
of color, gloss retention and durability.
Washing Your Vehicle
The best way to preserve your vehicle's finish is to keep
it clean by washing it often with lukewarm or cold water.
Don't
wash your vehicle in the direct rays of the sun.
Don't use strong soaps or chemical detergents. Use
liquid hand, dish or car washing (mild detergent) soaps.
Don't use cleaning agents that are petroleum based, or
that contain acid or abrasives. All cleaning agents
should be flushed promptly and not allowed to dry on
the surface, or they could stain. Dry the finish with a
soft, clean chamois or a 100% cotton towel to avoid
surface scratches and water spotting.
High pressure vehicle washes may cause water to enter
your vehicle.
6-62