Buick 1999 LeSabre Owner's Manual page 326

Long Trip/Highway Scheduled Maintenance
The system won't detect dust in the oil. So if you drive in
a dusty area, be sure to change your oil and filter every
3,000 miles (5 000 km) or sooner if the CHANGE OIL
SOON light comes on. Remember to reset the Oil Life
Monitor whenever the oil is changed. For more
information, see CHANGE OIL SOON Light in the Index.
+ A good time to check your brakes is during tire
rotation. See "Brake System Inspection" under "Periodic
Maintenance Inspections" in Part C of this schedule.
7-24
++ If you drive in a highly corrosive environment, your
brake calipers may require additional inspection and
service, at every other tire rotation. See "Caliper/Knuckle
Maintenance Inspection" under "Periodic Maintenance
Inspections" in Part C of this schedule.
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