At Least Once A Year; Key Lock Cylinders Service; Underbody Flushing Service - Chevrolet kodiak 2004 Owner's Manual

Hood Latches Check
Check that the hood closes firmly. Check for broken,
damaged, loose or missing parts that might prevent tight
latching. Make sure the secondary latch (if equipped)
keeps the hood from opening all the way when the
primary latch is released.
Fluid Leaks Check
Check for fuel, coolant, oil or other fluid leaks by looking
at the surface beneath the vehicle after it has been
parked for awhile.
Underbody Inspection
Corrosive materials used for ice, snow removal and dust
control can collect on the underbody. If these materials
are not removed, accelerated corrosion (rust) can
occur on underbody parts such as fuel lines, frame, floor
pan and exhaust system. At least every spring, flush
these materials from the underbody with plain
water. Take care to clean well any areas where mud
and other debris can collect. Sediment packed in closed
areas of the frame should be loosened before being
flushed.
6-28
Engine Cover Check
Check that the cab's engine cover and seal (if equipped)
are not torn or damaged. Be sure that the cover is
clamped down firmly to the floor.

At Least Once a Year

Key Lock Cylinders Service

Lubricate the key lock cylinders with the lubricant
specified in Part C.

Underbody Flushing Service

At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
Tractor Protection (Breakaway) Valve
Check
On air brake models, remove, disassemble, clean and
inspect the tractor protection (breakaway) valve.