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10.2 External Inspection (School Bus, Truck/Tractor)

Steering

Steering box/hoses:
  • Check that the steering box is securely mounted and not leaking. Look for any missing nuts, bolts and cotter keys.
  • Check for power steering fluid leaks or damage to power steering hoses.
Steering linkage:
  • See that connecting links, arms and rods from the steering box to the wheel are not worn or cracked.
  • Check that joints and sockets are not worn or loose and that there are no missing nuts, bolts or cotter keys.

Suspension

Springs/air/torque:
  • Look for missing, shifted, cracked or broken leaf springs.
  • Look for broken or distorted coil springs.
  • If vehicle is equipped with torsion bars, torque arms or other types of suspension components, check that they are not damaged and are mounted securely.
  • Air ride suspension should be checked for damage and leaks.
Mounts:
  • Look for cracked or broken spring hangers, missing or damaged bushings and broken, loose or missing bolts, Ubolts or other axle mounting parts. (The mounts should be checked at each point where they are secured to the vehicle frame and axle(s))
Shock absorbers:

Check that shock absorbers are secure and that there are no leaks.

Note: Be prepared to perform the same suspension components inspection on every axle (power unit and trailer, if equipped).

Brakes

Slack adjusters:
  • Look for broken, loose or missing parts.
  • The angle between the push rod and adjuster arm should be a little over 90 degrees when the brakes are released and not less than 90 degrees when the brakes are applied.
  • When pulled by hand, the brake rod should not move more than 1 inch (with the brakes released).
  • The manual adjustment of automatic slack adjusters is dangerous because it gives the vehicle operator a false sense of security about the effectiveness of the braking system.
Brake chambers:

Check that brake chambers are not leaking, cracked or dented and are securely mounted.

Brake hoses/lines:

Look for cracked, worn or leaking hoses, lines and couplings.

Drum brake:
  • Check for cracks, dents or holes. Also check for loose or missing bolts
  • Brake linings (where visible) should not be worn dangerously thin.
Brake linings:

On some brake drums there are openings where the brake linings can be seen from outside the drum. For this type of drum, check that a visible amount of brake lining is showing (at least 1/4-inch).

Note: Be prepared to perform the same brake components inspection on every axle (power unit and trailer, if equipped).

Wheels

Rims:

Check for damaged or bent rims. Rims cannot have welding repairs.

Tires:

The following items must be inspected on every tire:

  • Tread depth - Check for minimum tread depth (4/32-inch on steering axle tires, 2/32-inch on all other tires).
  • Tire condition - Check that tread is evenly worn and look for cuts or other damage to tread or sidewalls. Also, make sure that valve caps and stems are not missing, broken or damaged.
  • Tire inflation - Check for proper inflation by using a tire gauge or by striking tires with a mallet or other similar device.

Note: You will not get credit if you simply kick the tires to check for proper inflation.

Hub oil seals/axle seals:
  • Check that hub oil/grease seals and axle seals are not leaking and, if wheel has a sight glass, oil level is adequate.
Lug nuts:
  • Check that all lug nuts are present, free of cracks and distortions, and show no signs of looseness such as rust trails or shiny threads.
  • Make sure all bolt holes are not cracked or distorted.
Spacers:
  • If equipped, check that spacers are not bent, damaged or rusted through
  • Spacers should be evenly centered, with the dual wheels and tires evenly separated.

Note: Be prepared to perform the same wheel inspection on every axle (power unit and trailer, if equipped).

After pointing to the location of the steering box and hoses, tell the examiner: "I am checking the steering box and hoses to make sure they are securely mounted, not leaking any fluid and has no missing nuts or bolts. I am also making sure the hoses are in good condition and are not leaking."
Once you have indicated the location of the steering linkage, tell the examiner: "I am checking the steering linkage from the steering box to the wheel to make sure it is not worn or cracked. I'm also making sure the joints and sockets are not worn or loose, and there are no missing nuts, bolts, or cotter pins."
After pointing out the location of the leaf springs and air bags, tell the examiner: "I am checking to make sure the leaf springs are not cracked, bent or broken and haven't shifted. I am also checking that the air bags are properly mounted and are not leaking."
After you have indicated where the spring hangers are located, tell the examiner: "I am now making sure the spring hangers are not cracked, bent, broken, or missing. There no missing bolts and all bolts are in place."
Once you pointed out where the shock absorber is located, tell the examiner: "I am checking the shock absorber to make sure it is properly mounted on both ends, not bent, broken, or leaking."
Show the examiner where the slack adjuster is located and then say: "The slack adjuster and pushrod should be securely mounted, not cracked, bent, or broken. When the brakes are released and pulled by hand, the rod should not move more than approximately 1-inch."
Point out the brake chamber, then tell the examiner: "The brake chamber should not be dented or cracked and it should be mounted securely with no leaks."
Point out some hoses and lines to the examiner, then say "I am now making sure all hoses and lines are securely mounted, have no abrasions, bulges, or cuts, and are not leaking."
After indicating the location of a brake drum, tell the examiner: "The brake drum should not be cracked, bent, or broken. It must be securely mounted and free from oil or debris."
Once you show the examiner where the brake linings are located, tell the examiner, "Brake linings should be securely mounted, not cracked, no dents or holes, no loose or missing bolts, and the linings should have at least 1/4 inch of friction material."
After pointing out a rim, tell the examiner: "I am checking to make sure the rims are not cracked, bent, or broken and have no welds."
While checking a tire, tell the examiner: "The tread needs to be evenly worn and have no abrasions, bulges, or cuts to the tread or sidewalls. Tread depth should be 4/32-inch in each and every major groove on steer tires and 2/32-inch in each and every major groove on all other tires. Inflation on steer tires must be checked using a tire gauge and all other tires can be checked by striking the side of the tire."
Locate an axle seal and say to the examiner: "The axle seal must be securely mounted, can't be leaking, and the fluid should be filled to normal range."
Point out the lug nuts and say to the examiner: "All lug nuts must be present and not loose. A sign of loose lug nuts would be rust trails around the threads or powder residue. There should also be no cracks around the bolt holes.
Indicate where the spacer is located and tell the examiner: "There should be adequate spacing and the space should be free from foreign objects. The spacer should not be cracked, bent, broken or excessively rusted.

CDL:

Commercial Driver's License (CDL)

A CDL is required to drive any of the following vehicles:

  • Any combination of vehicles with a gross combined weight rating (GCWR) of 26,001 or more pounds, providing the gross vehicle weight rating (GVWR) of the vehicle being towed is in excess of 10,000 pounds.
  • Any single vehicle with a GVWR of 26,001 or more pounds, or any such vehicle towing another not in excess of 10,000 pounds.
  • Any vehicle, regardless of size, designed to transport 16 or more persons, including the driver.
  • Any vehicle required by federal regulations to be placarded while transporting hazardous materials.

HOS:

Hours Of Service

HOS refers to the logbook hours of service regulations.

OWI:

Operating While Intoxicated

OOS:

When a violation by either a driver or company is confirmed, an out-of-service order removes either the driver or the vehicle from the roadway until the violation is corrected.

Review Questions - Click On The Picture To Begin...

What is the minimum amount of tread depth allowed on a drive axle or trailer axle?
  • 1/2-inch
  • 2/32-inch
  • 1-inch
  • 4/32-inch

Quote From The CDL Manual:

Tires: The following items must be inspected on every tire:

  • Tread depth - Check for minimum tread depth (4/32-inch on steering axle tires, 2/32-inch on all other tires).
  • Tire condition - Check that tread is evenly worn and look for cuts or other damage to tread or sidewalls. Also, make sure that valve caps and stems are not missing, broken or damaged.
  • Tire inflation - Check for proper inflation by using a tire gauge or by striking tires with a mallet or other similar device.

TruckingTruth's Advice:

When checking a drive tire, tell the examiner:

"I'm checking the drive tire to make sure the tread is evenly worn and there are no abrasions, bulges, or cuts to the tread or sidewalls. The tread must have a minimum depth of 2/32 of an inch. The tires must be properly inflated according to factory specifications. I'm also making sure there is proper spacing between the dual tires and the space is free from foreign objects."

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When inspecting suspension components, you must:
  • Check the components on the tractor only
  • Check the components for every axle
  • Check the components on the trailer only
  • Checking suspension components is not required

Quote From The CDL Manual:

Springs/air/torque:

  • Look for missing, shifted, cracked or broken leaf springs.
  • Look for broken or distorted coil springs.
  • If vehicle is equipped with torsion bars, torque arms or other types of suspension components, check that they are not damaged and are mounted securely.
  • Air ride suspension should be checked for damage and leaks.

Mounts:

Look for cracked or broken spring hangers, missing or damaged bushings and broken, loose or missing bolts, Ubolts or other axle mounting parts. (The mounts should be checked at each point where they are secured to the vehicle frame and axle(s)).

Shock absorbers:

Check that shock absorbers are secure and that there are no leaks.

Note: Be prepared to perform the same suspension components inspection on every axle (power unit and trailer, if equipped).

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Next
Which statement about inspecting the steering box is incorrect?
  • Make sure there is a small amount of steering fluid dripping from the bottom of the steering box
  • All of these answers are correct
  • Look for any missing nuts, bolts, and cotter pins
  • Check for damaged hoses leading to the steering box

Quote From The CDL Manual:

Steering box/hoses:

  • Check that the steering box is securely mounted and not leaking. Look for any missing nuts, bolts and cotter keys.
  • Check for power steering fluid leaks or damage to power steering hoses.

TruckingTruth's Advice:

After pointing out the steering box and hoses, tell the examiner:

"I am making sure the steering box is properly mounted and secured, not cracked bent or broken, and not leaking fluid. I'm also making sure all the hoses are not damaged or leaking."

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Can rims have welding repairs?
  • Yes, but the rim has to be replaced within 1 year of the weld being made
  • No, rims cannot have welding repairs
  • Yes, but any welds must be made by a certified mechanic
  • Yes, welding is allowed on rims

Quote From The CDL Manual:

Rims: Check for damaged or bent rims. Rims cannot have welding repairs.

TruckingTruth's Advice:

While inspecting a rim during your pre-trip exam, tell the examiner:

"I am checking the rim to make sure it is not cracked, bent, or broken and contains no welds."

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Next
What part does the following inspection refer to: All are present, free of cracks and distortions, and show no signs of looseness such as rust trails or shiny threads.
  • Axle Seals
  • Brake Linings
  • Slack Adjusters
  • Lug Nuts

Quote From The CDL Manual:

Lug nuts:

  • Check that all lug nuts are present, free of cracks and distortions, and show no signs of looseness such as rust trails or shiny threads.
  • Make sure all bolt holes are not cracked or distorted.

TruckingTruth's Advice:

During the pre-trip exam, you'll want to mention the lug nuts for each wheel. You should say:

"All lug nuts are present, not loose, and there are no rust trails around the nuts or cracks around bolt holes."

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Next
What part requires that you check the connecting links, arms and rods from the steering box to the wheel are not worn or cracked?
  • Steering linkage
  • Slack adjusters
  • Kingpin
  • Drive shaft

Quote From The CDL Manual:

Steering linkage:

  • See that connecting links, arms and rods from the steering box to the wheel are not worn or cracked.
  • Check that joints and sockets are not worn or loose and that there are no missing nuts, bolts or cotter keys.

TruckingTruth's Advice:

After pointing out the steering linkage, tell the examiner:

"I'm checking the steering linkage from the steering box to the wheel and making sure it is not worn, cracked, bent, or broken. I'm also making sure all joints and sockets are not worn or loose with no missing nuts, bolts, or cotter pins."

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While inspecting the brake chamber, you should:
  • You should do all of these things
  • Check for air leaks
  • Make sure it's properly mounted and secure
  • Look for cracks and dents

Quote From The CDL Manual:

Brake chambers: Check that brake chambers are not leaking, cracked or dented and are securely mounted.

TruckingTruth's Advice:

After pointing out the location of a brake chamber, tell the examiner:

"I am now inspecting the brake chamber to make sure it's not cracked, bent, or broken. I'm also making sure it is properly mounted and secure and is not leaking."

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Next
When pulled by hand, how much should a brake rod move when the brakes are released?
  • No more than 1 inch
  • No more than 1/2 inch
  • No more than 1.5 inches
  • No more than 2 inches

Quote From The CDL Manual:

Slack adjusters:



       
  • Look for broken, loose or missing parts.

  •    
  • The angle between the push rod and adjustor arm should be a little over 90 degrees when the brakes are released and not less than 90 degrees when the brakes are applied.

  •    
  • When pulled by hand, the brake rod should not move more than 1 inch (with the brakes released).

  •    
  • The manual adjustment of automatic slack adjusters is dangerous because it gives the vehicle operator a false sense of security about the effectiveness of the braking system.

TruckingTruth's Advice:

While inspecting the slack adjuster and push rod, you should tell the examiner:

"I am now checking the slack adjuster and push rod to be sure they are properly mounted and secure, not cracked, bent, or broken. When the brakes are released and pulled by hand, the rod should not move more than approximately 1 inch."

Prev
Next
What is the minimum amount of tread depth allowed on a steering axle?
  • 2/32-inch
  • 1/2-inch
  • 1-inch
  • 4/32-inch

Quote From The CDL Manual:

Tires: The following items must be inspected on every tire:

  • Tread depth - Check for minimum tread depth (4/32-inch on steering axle tires, 2/32-inch on all other tires).
  • Tire condition - Check that tread is evenly worn and look for cuts or other damage to tread or sidewalls. Also, make sure that valve caps and stems are not missing, broken or damaged.
  • Tire inflation - Check for proper inflation by using a tire gauge or by striking tires with a mallet or other similar device.

TruckingTruth's Advice:

When checking a steer tire, say to the examiner:

"I'm checking the steer tire to make sure the tread is evenly worn and there are no abrasions, bulges, or cuts to tread or sidewalls. The tread must have a minimum depth of 4/32 of an inch. The tires must be properly inflated according to factory specifications. Tire inflation on steer tires must be checked with a tire gauge."

Prev
Next
Axle Seals can also be called:
  • Pipe seals
  • Rim oil seals
  • Hub oil seals
  • Drive seals

Quote From The CDL Manual:

Hub oil seals/axle seals:

Check that hub oil/grease seals and axle seals are not leaking and, if wheel has a sight glass, oil level is adequate.

TruckingTruth's Advice:

When checking an axle seal, tell the examiner:

"I'm checking the axle seal to make certain it is securely mounted, not damaged, and not leaking."

If a sight glass is present, say "I'm checking the sight glass to make sure the fluid is at the proper level."

Note: Not all axle seals have a sight glass.

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