What is a Pre-Trip Inspection for Class B CDL?

What is a pre-trip inspection?

A pre-trip inspection is a thorough review and examination of a commercial vehicle's major systems and parts before heading out on a route. Completing the pre-trip inspection is one of the most common and important tasks commercial drivers must perform. Drivers have to perform this vehicle inspection at the start of a new day, every 24-hours, and whenever they change vehicles. After completing this inspection, drivers must complete a driver vehicle inspection report (DVIR) recording the completed inspection.

Pre-trip inspections for class B licensees

The class B commercial driver’s license (CDL) covers both passenger carrying and non-passenger vehicles. These might include straight trucks, box trucks, large passenger buses, dump trucks, waste collection trucks, tractor-trailers and more. Depending on the vehicle driven, the class B pre-trip inspection may have slight variations. 

The Department of Transportation (DOT) requires drivers to perform a pre-trip inspection before driving a commercial vehicle. Similar to Class A CDL holders, the actual daily pre-trip inspection takes about 15 minutes or less. Typically, the inspection includes the following with employer and business-specific inspections.

• Brakes and air system

• Steering mechanism

• Lights and reflectors

• Tires, wheels, and rims

• Windshield wipers

• Rearview mirrors

• Emergency equipment

Class B CDL pre-trip inspection checklist

When getting a CDL, passing the pre-trip inspection test is much more intensive than the pre-trip inspections drivers perform while on the job. This pre-trip inspection checklist for a Class B CDL gives drivers an overview of what and how to perform an inspection. Check your state’s CDL manual for a complete list of inspection requirements.

See Class A pre-inspection checklist here.

Engine compartment

• Fluids - coolant, oil, and power steering: Reservoirs and tanks should not leak. Check hoses for splits or cuts and that they are securely mounted on both ends. Verify proper fluid levels with a dipstick.

• Belts - alternator, pumps, compressor: All belts should be securely mounted without cracks or frays. Belt should have no more than 1/2" to 3/4" of play. 

• Hoses (passenger and driver’s sides): All hoses, including the power steering hose and coolant hose, should be secured on both ends. They should not have splits, cuts, or leaks.

• Air compressor: May be difficult to see. Ensure it’s securely mounted, not broken, cracked or leaking.

• Alternator: All wires are properly connected.

• Water pump: All hoses are properly connected and not leaking. 

Front of vehicle

• Steering gearbox and hoses: No damage or leaks. Hose should be secured on both ends. They should not have splits, cuts, or leaks.

• Steering shaft/steering column: Not bent or broken.

• Pitman arm: All caste nuts and cotter pins are present and tight.

• Drag link: Rubber is not split and properly greased.

• Upper and lower control arms and tie rod: Tie rod should be secure, not cracked or bent.

Front suspension

• Spring mounts/spring hanger: Not cracked or broken

• Leaf springs: None are cracked, broken, or shifted.

• U-bolts: All accounted for.

• Shock absorber: No visible leaks. Leaks will show at the point where the top and bottom of the shock meet. Rubber is not split or shows signs of dry rot.

• Airbag: Check rubber for abrasions, cuts or audible leaks plus any missing bolts.

Side of cab and under vehicle

• Mirrors and bracket: Hardware attached properly. Mirror should be clean and not broken.

• Door and hinges: Demonstrate door operations, latching properly, hinges intact. Door seals should not be torn or rotten. 

• Steps: Mounted properly and can hold weight.

• Fuel tank: Not leaking; cap is tight with seal intact.

• Catwalk (if applicable): Properly mounted and clear of loose objects.

• Baggage compartment (if applicable):  Demonstrate door operations, latching properly, hinges intact. Door seals should not be torn or rotten. 

• Drive shaft: Not twisted, U-joints not broken and free of debris.

• Exhaust system: Not loose, no sign of leaks (exterior soot).

• Frame: Nothing broken or unauthorized welds.

Brake system (both tractor and trailer)

• Brake hose: Securely mounted on both ends. No splits, cuts, and not leaking audibly leaking air.

• Brake chamber: Not audibly leaking air.

• Slack adjuster and push rod: When brakes are released and pulled by hand, the push rod should have no more than 1” of play. It should stay at a 90° angle to the brake chamber.

• Brake drum:  No bluing from excessive heat.

• Brake pads/brake lining: Check for oil and debris on the lining. Minimum brake pad thickness is ¼.” 

Wheel system

• Wheel rims: No unauthorized or illegal welds.

• Steer tires: Look for cuts, bulges, and abrasions on the tread and sidewalls. Tread depth should be a minimum of 4/32”. Tread should be evenly worn. Check inflation levels on tires with an air gauge, filled to manufacturer’s specifications.

• Drive tires: Look for cuts, bulges, and abrasions on the tread and sidewalls. Tread depth should be a minimum of 2/32”. Tread should be evenly worn. Check inflation levels on tires with an air gauge, filled to manufacturer’s specifications.

• Valve stem. Properly secured, metal cap in place. Not audibly leaking air.

• Lug nuts: All accounted for. Check for rust or cracks.

• Hub seal/axle seal: Should not be loose. No visible leaks.

• Spacing (if applicable): There must be proper spacing between the tires if equipped with duals.

Rear suspension

• Airbag: Check rubber for abrasions, cuts or audible leaks, plus any missing mounting bolts.

• Spring mounts/spring hanger: Not cracked or broken

• Leaf springs: None are cracked, broken, or shifted.

• U-bolts: All accounted for.

• Torque arm/radius rod: Secure mounting, bushings intact.

Rear of vehicle

• Doors and hinges (if applicable): Secured and should open, close and latch properly. Door seals have no separation, no rubber tubing sticking out.

• Mudflap: Secured, not missing or broken. At the right height.

Lights and reflectors

Check all lights on the front, both sides, vehicle rear. Turn on to ensure lights and reflectors are working.

• Running lights: Walk around the vehicle to examine all.

• High beams/low beams: Walk around the vehicle to examine all.

• Turn signals: Signal both right turn and left turn. Walk around the vehicle to examine all.

• Hazards/4-way flashers and clearance light: Walk around the vehicle to examine all.

• Brake lights: Ask the examiner to watch brake lights. Confirma they worked using the side mirror. 

• License plate lights: Walk around the vehicle to examine all.

• Reflector tapes: Clean and not worn. Walk around the vehicle to examine all.

Passenger items

• Doors and hinges (if separate from driver door): Secured and should open, close and latch properly. Door seals have no separation, no rubber tubing sticking out.

• Wheelchair lift: No wear, damage, or other abnormal conditions.

• Handrails and step lights: Handrail mounted firmly, bolts accounted for. Step lights are all working.

• Emergency exits: Labeled and able to open and close. If there is an alarm for the door, ensure it works when the door is open.

• Seating: Not torn, securely mounted.

School bus items

• Student loading lights: Walk around the vehicle to examine all. None cracked or broken. All lights able to flash.

• Stop/safety arm: Able to fully extend with lights 

• Student mirror: Secure, not cracked or broken. No obstructions and properly adjusted.

• First aid and body fluid cleanup kit: Labeled and stocked with supplies. Nothing expired.

In-cab inspection and air brake test

• Seat belt: No rips or frays and should adjust and latch properly.

• Lighting indicators: See lights and reflectors section

• Oil pressure indicator: Demonstrate normal operating range.

• Water temperature gauge: Demonstrate normal operating range.

• Air pressure gauges: Build to governor cut out.

• Ammeter/voltmeter: Charging between 13 and 14 volts.

• Mirrors: Secure, not cracked or broken. No obstructions and properly adjusted.

• Windshield: No more than a 1” crack is permitted. Clean and free of debris.

• Windshield wipers and washers: Turn on to show they are working properly.

• Horns (city and air): Show they are working properly.

• Heater/defroster: Turn on to show they are working properly.

• Safety/emergency equipment: Must have fire extinguisher, three red reflective triangles and spare electrical fuses. Extinguisher must be fully charged and secured.

• Steering wheel: Secured to steering column.

• Foot pedals: Free of grease and debris. No obstructions. 

• Hydraulic brake check: Pump the brake pedal several times. Apply pressure to the pedal and hold for five seconds. The pedal should not move.

• Air brake check: Air brake devices vary. Drivers must test three components of the air brake check correctly: applied pressure, warning lights and buzzers, and valve pop-outs.

• Parking brake: Apply and put the vehicle in low gear and try to move. Drivers must test separate brakes (tractor and trailer) individually.

• Service brake: Release brakes. Drive 3 – 5 mph. Apply the service brake and come to a complete stop. Ensure steering does not pull to the left or right when applying the brakes.