GMC TopKick 2007 Owner's Manual page 388

(22) = Wheel bearing service:
•
Grease type — Clean, inspect, and lubricate
with the proper wheel bearing grease at
designated intervals or when hubs are
removed. See Part C: Recommended Fluids
and Lubricants on page 397.
•
Oil-filled type — Some wheel bearings are
lubricated by axle lubricant. When you
have oil-filled hubs, use lubricant identical
to that used in the axle. Lubricant change
intervals are the same for front and rear axles.
However, you must maintain the proper
oil level between change intervals. See
Front Wheel Bearings with Oil-Filled Hubs
on page 319 and Part C: Recommended
Fluids and Lubricants on page 397.
(23) = Check the air intake system installation
to see that gaskets are seated properly and
all hose connections, fasteners, and other
components are tight. Tighten connections
and fasteners or replace parts as required.
388
(24) = Evaporative Control System Service,
if equipped: Check all fuel and vapor lines and
hoses for proper connections and correct routing
(or every 24 months, whichever occurs first).
Replace parts as needed.
(25) = Replace spark plugs. Inspect wires for
damage. Check the wire boot and boot heat
shield fit at spark plugs and coil. Replace parts
as needed.
(26) = Check the fuel tank, fuel cap and fuel lines
for damage which could cause leakage. Inspect
fuel cap for correct sealing ability and any
indications of damage. Check fuel cap gasket
for even filler neck imprint. Replace parts as
needed.
(27) = Check Exhaust Gas Recirculation (EGR)
system as described in the service manual.
See Service Publications Ordering Information
on page 415.