Footnotes — Maintenance Schedule Additional Required Services — Severe
a) Or every two years, whichever comes first.
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 10‑14.
f) Or every 10 years, whichever comes first. Inspect for fraying, excessive cracking, or damage;
replace, if needed.
See also:
Driving on Grades
Reduce speed and shift to a lower gear before starting down a long or steep downgrade.
If the transmission is not shifted down, the brakes might have to be used so much
that they would get hot and ...
General Information
For service and parts needs, visit your dealer. You will receive genuine GM parts
and GM-trained and supported service people. Genuine GM parts have one of these
marks:
...
Trailer Towing
If the vehicle has a diesel engine, see the Duramax diesel supplement for more information.
If the vehicle is a hybrid, see the hybrid supplement for more information.
Do not tow a trailer during br ...





