2003 GMC YUKON radiator

97,500 Miles (162 500 km)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-61for proper rotation pattern and additional
information.(See footnote +.)
100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission Control
Service.
❑Replace spark plugs.An Emission Control Service.
❑Change automatic transmissionuid andlter if
the vehicle’s GVWR is over 8,600 lbs or if the vehicle
is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
In hilly or mountainous terrain.When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
❑If you haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmissionuid, change
both theuid andlter.
❑Change transfer caseuid.
❑Except 8.1L V8 Engine: Inspect Positive Crankcase
Ventilation (PCV) valve.An Emission Control
Service.
150,000 Miles (240 000 km)
❑Drain,ush and rell cooling system (or every
60 months since last service, whichever occursrst).
SeeEngine Coolant on page 5-26for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.An Emission Control Service.
❑Inspect engine accessory drive belt.An Emission
Control Service.
6-10
2003 - Yukon/Yukon XL

Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
ttings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
Transfer Case and Front Axle
(Four-Wheel Drive) Inspection
Every 12 months or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary. Auid loss could indicate a problem;
check and have it repaired, if needed. On manual
shift transfer case, oil the control lever pivot point. Check
vent hose at transfer case for kinks and proper
installation. More frequent lubrication may be required
on off-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook-up, binding, leaks, cracks,
chang, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.
6-16
2003 - Yukon/Yukon XL