Frequent Low-speed Operation, Consistent Heavy Traffic Under 25 mph (40 km/h) or
Long Rush-hour Traffic
Change the engine oil and filter as indicated by the
information display, and perform the services listed in the
scheduled maintenance chart. As required
Replace the engine-mounted and frame-mounted fuel
filters. Every 15,000 mi
(24,000 km), six months or
600 engine hours
Inspect the coolant concentration, freeze-point protection
and additive, corrosion inhibitor strength. Add coolant
additive if necessary. Every 30,000 mi
(48,000 km) or 1200 engine
hours
Flush and refill the coolant. Do not add coolant additive. Every 60,000 mi
(96,000 km) or 2400
engine hours
Note:When adding coolant additive, do not exceed the specified maximum of 47 fl oz
(1.4 L) for the engine and 20 fl oz (473 ml) for the secondary cooling system. Operating the
engine with excessive coolant additive may cause overheating which could lead to severe,
permanent engine damage.
Note:After the initial coolant flush and fill at 60,000 mi (96,000 km) or 2400 engine
hours, flush and fill every 45,000 mi (72,000 km) or 1800 engine hours thereafter.
333
Scheduled Maintenance
Sustained High-speed Driving at Gross Vehicle Weight Rating, Maximum Loaded Weight
for Vehicle Operation
Change the engine oil and filter as indicated by the
information display, and perform the services listed in the
scheduled maintenance chart. As required
Replace the engine-mounted and frame-mounted fuel
filters. Every 15,000 mi
(24,000 km), six months or
600 engine hours
Inspect the coolant concentration, freeze-point protection
and additive, corrosion inhibitor strength. Add coolant
additive if necessary. Every 30,000 mi
(48,000 km) or 1200 engine
hours
Flush and refill the coolant. Do not add coolant additive. Every 60,000 mi
(96,000 km) or 2400
engine hours
Note:When adding coolant additive, do not exceed the specified maximum of 47 fl oz
(1.4 L) for the engine and 20 fl oz (473 ml) for the secondary cooling system. Operating the
engine with excessive coolant additive may cause overheating which could lead to severe,
permanent engine damage.
Note:After the initial coolant flush and fill at 60,000 mi (96,000 km) or 2400 engine
hours, flush and fill every 45,000 mi (72,000 km) or 1800 engine hours thereafter.
Operating in Sustained Ambient Temperatures Below -9.4°F (-23°C) or Above 100.3°F
(38°C)
Change the engine oil and filter as indicated by the
information display, and perform the services listed in the
scheduled maintenance chart. As required
Replace the engine-mounted and frame-mounted fuel
filters. Every 15,000 mi
(24,000 km), six months or
600 engine hours
Operating in Dusty or Sandy Conditions, Such as Unpaved or Dusty Roads
Rotate the tires1, inspect the tires for wear and measure
tread depth. Every 7,500 mi (12,000 km)
Inspect the brake system pads and rotors.
Inspect the air filter restriction gauge. Replace the filter if
necessary.
334
Scheduled Maintenance
