GMC 2012 Terrain Owner's Manual page 378

11-6 Service and Maintenance
Footnotes Maintenance
Schedule Additional Required
Services Normal
a) Or every two years, whichever
comes first. More frequent
replacement may be needed if
the vehicle is driven in areas with
heavy traffic, areas with poor air
quality, or areas with high dust
levels. Replacement may also be
needed if there is a reduction in air
flow, excessive window fogging,
or odors.
b) Check all fuel and vapor lines
and hoses for proper hook up,
routing, and condition. Check that
the purge valve, if the vehicle has
one, works properly. Replace as
needed.
c) Or every four years, whichever
comes first.
d) Do not directly power wash
the transfer case output seals.
High pressure water can overcome
the seals and contaminate the
transfer case fluid. Contaminated
fluid will decrease the life of the
transfer case and should be
replaced.
e) Or every five years, whichever
comes first. See Cooling System on
page 10 16.
f) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.