Buick 1993 Skylark Owner's Manual page 276

Inspect hoses and replace if they are cracked,
swollen or deteriorated. Tighten screw-type hose
clamps. Clean the outside of the~radiator and air
conditioning condenser. Wash the pressure cap and
neck.
To help ensure proper operation, we recommend a
pressure test
of
both the cooling system and the
pressure cap.
7. Transaxle Service -- Change both the fluid and
filter every 15,000 miles (25 000 km) if the vehicle
is mainly driven under one or more of these
conditions:
0
In heavy city traffic where the outside
temperature regularly reaches 90
F
(32 C) or
higher.
0
In hilly or mountainous terrain.
When doing frequent trailer towing. (With some
models, you shouldn't ever tow a trailer. See
"Towing a Trailer" in the Index.)
Uses such as found in taxi, police car or delivery
service.
If you do' not use your vehicle under any of these
conditions, change both the fluid and filter every
100,000 miles (160 000 km).
8. Spark Plug Replacement* -- Replace spark plugs
with the proper type. See "Specifications Chart" in
the Index.
9. Spark Plug Wire Inspection (3.3L Code N engine
only)*? -- Inspect for burns, cracks or other
damage. Check the boot fit at the coils and at the
spark plugs. Replace wires as needed.
10.
Air Cleaner Filter Replacement* -- Replace every
30,000 miles (50 000 km) or more often under dusty
conditions. Ask your dealer for the proper
replacement intervals for your driving conditions.
11.
Fuel Tank, Cap and Lines Inspection"? -- Inspect
fuel
tank,
cap and lines (including fuel rails and
injection assembly) for damage or leaks. Inspect fuel
cap gasket for an even filler neck imprint or any
damage. Replace parts as needed. Periodic
replacement of the fuel filter is not required.
*
An Emission Control Service.
The U.S. Environmental Protection Agency has determined that the failure
to
perform this maintenance item will not nullify the emission warranty or limit recall liability prior to the completion of vehicle
useful life. General Motors, however, urges that all recommended maintenance services be performed at the indicated intervals and the maintenance be recorded in "Section EMaintenance Record".