While maintenance and repair costs vary from truck to truck, Fleet Advantage broke down the top ten costly repairs for Class 8 vehicles in their Mitigating Rising Maintenance & Repair Costs for Class 8 Truck Fleets downloadable report. 

1. Tires, tubes, liners and valves (43 percent of total maintenance and repair cost)
2. Preventive maintenance (12 percent)
3. Brakes (9 percent)
4. Expendable items (8 percent)
5. Exhaust system (6 percent)
6. Fuel system (6 percent)
7. Lighting system (5 percent)
8. Cranking system (5 percent)
9. Power plant (3 percent)
10. Engine/motor systems (3 percent)

Some of the highest-cost items, according to Fleet Advantage, include: 

• Equipment issues combined with warranty expiration:
• Emissions issues - DPF cleaning or replacement
• Engine components beign to fail
• Brake issues. At about 250,000 miles this cost jumps significantly, Fleet Advantage says. 
• Lack of follow-up repairs
• Tire wear
• Unforeseen breakdowns which result in repair cost, but also increased driver downtime, customer delays, load damage, towing expenses and more.