Volvo VNL 780 Operator's Manual page 307

Brakes
Dragging brakes increase fuel consumption. They should be checked regularly. It is
important that the release action of the air valves is fast and that the moving parts of the
wheel brakes are checked for good adjustment and operation.
Axles
An axle out of alignment increases rolling resistance. Regularly check the front wheel
alignment and axles on both the tractor and trailer/semi-trailer. If they are correct, there will
be less rolling resistance and, therefore, lower fuel consumption.
A good sign of an axle or wheel out of alignment is uneven tire wear. Check the tires often.
Engine
Faulty or incorrectly adjusted engine components increase fuel consumption. The list below
gives some typical components that can influence fuel consumption:
•
Blocked (on the outside) charge air cooler/radiator package
•
Faulty thermostat
•
Blocked fuel filters
•
Blocked air intake filter
•
Faulty injectors
•
Dirty turbocharger
•
Air in fuel system
•
Faulty fuel supply pump
•
Faulty fuel relief valve
•
Faulty fan thermostat/clutch
OPERATION 297