Chevrolet Low Cab Forward 4500 2019 Series Owner's Manual page 149

148 Driving and Operating
Symptom
Not enough engine power
Brakes not effective
Cause
Parking brake not fully
released
Brake dragging
Air cleaner clogged
Fuel filter clogged
Engine control system
faulty
Common rail system
faulty
Engine faulty
Drum-to-lining gap too
large
Air in brake fluid
Brake system failure
Corrective Action
Make sure it is fully
released
Reference
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