GMC 2012 Savana Owner's Manual page 342

Use a soft, clean cloth with mild
soap and water to clean the wheels.
After rinsing thoroughly with clean
water, dry with a soft, clean towel.
A wax may then be applied.
Keep the wheels clean using a soft,
clean cloth with mild soap and
water. Rinse with clean water. After
rinsing thoroughly, dry with a soft,
clean towel. A wax may then be
applied.
Visually inspect front and rear
suspension and steering system for
damaged, loose, or missing parts
or signs of wear. Inspect power
steering lines and hoses for proper
hook-up, binding, leaks, cracks,
chafing, etc. Visually check constant
velocity joints, rubber boots, and
axle seals for leaks.
Lubricate all key lock cylinders,
hood hinges, liftgate hinges, and
steel fuel door hinge unless the
components are plastic. Applying
silicone grease on weatherstrips
with a clean cloth will make them
last longer, seal better, and not stick
or squeak.
Use plain water to flush dirt and
debris from the vehicle's underbody.
Your dealer or an underbody car
washing system can do this. If not
removed, rust and corrosion can
develop.
If the vehicle is damaged and
requires sheet metal repair or
replacement, make sure the body
repair shop applies anti-corrosion
material to parts repaired or
replaced to restore corrosion
protection.