310T Preventive Maintenance and Inspection 4 — Questions and Answers
Question 1: During a pre-trip inspection, a technician notices the steering wheel has more than 2 inches of free play on a vehicle with a 20-inch steering wheel. What action is required?
- Document and monitor at next service interval
- Place the vehicle out of service immediately (Correct answer)
- Adjust the steering gear box and continue the route
- Lubricate the steering column and recheck
Correct answer: Place the vehicle out of service immediately
Excessive steering wheel free play exceeding FMCSA limits requires placing the vehicle out of service until repaired.
Question 2: When inspecting air dryer cartridges during a preventive maintenance service, which condition indicates the desiccant must be replaced?
- Cartridge has been installed for 12 months regardless of condition
- Oil contamination is visible in the desiccant bed (Correct answer)
- The purge cycle takes longer than 3 seconds
- Outlet air pressure drops below 100 psi
Correct answer: Oil contamination is visible in the desiccant bed
Oil contamination saturates and destroys the desiccant's ability to remove moisture, requiring immediate cartridge replacement.
Question 3: A coach technician is performing a Level I CVSA inspection and finds one brake lining worn to the wear indicator. What is the correct determination?
- Vehicle may continue operating if other brakes are within spec
- Only that axle's brakes must be replaced before continuing
- Vehicle must be placed out of service (Correct answer)
- Lining thickness must be measured and documented but service can continue
Correct answer: Vehicle must be placed out of service
Any brake lining worn to the wear indicator meets the CVSA out-of-service criteria and prohibits continued operation.
Question 4: What is the correct method for checking wheel bearing adjustment on a steer axle equipped with tapered roller bearings during a PM inspection?
- Apply grease, torque to 200 ft-lb, then back off one castellation
- Torque to 50 ft-lb while rotating hub, back off to nearest castellation, then re-torque to 50 ft-lb (Correct answer)
- Torque to 50 ft-lb while rotating hub, back off 1/4 turn, then install cotter pin
- Jack the axle, grab the tire at 3 and 9 o'clock, and check for play only
Correct answer: Torque to 50 ft-lb while rotating hub, back off to nearest castellation, then re-torque to 50 ft-lb
The standard tapered roller bearing adjustment procedure seats the rollers by torquing while rotating, then backs off to the nearest castellation to achieve proper end play.
Question 5: During a PM inspection of a coach's automatic transmission, the fluid appears dark brown and has a burnt odor. What is the MOST appropriate action?
- Add a quart of new fluid to dilute the degraded fluid
- Change the fluid and filter, then road test to check for slipping
- Flush the transmission and inspect the torque converter for damage (Correct answer)
- Note the condition and advise the customer to schedule service within 1,000 miles
Correct answer: Flush the transmission and inspect the torque converter for damage
Dark, burnt transmission fluid indicates severe overheating and potential internal damage, requiring a complete flush and torque converter inspection.
Question 6: A truck's power steering pump is being inspected. Fluid in the reservoir appears milky white. What does this condition indicate?
- Normal oxidation from high operating temperatures
- Water or coolant contamination in the power steering system (Correct answer)
- Excessive foam caused by a low fluid level
- Compatible fluid types were mixed during the last service
Correct answer: Water or coolant contamination in the power steering system
Milky or white fluid in the power steering reservoir indicates water or coolant intrusion, which can damage the pump and rack seals.
Question 7: When performing a PM inspection on a diesel engine, the technician finds the crankcase ventilation tube heavily coated with thick black sludge. What is the MOST likely cause?
- Normal blow-by accumulation requiring only cleaning
- Engine oil overdue for change or severe ring blow-by (Correct answer)
- Coolant leaking into the crankcase
- Incorrect viscosity oil used at the last service
Correct answer: Engine oil overdue for change or severe ring blow-by
Heavy sludge in the crankcase ventilation system indicates either severely degraded oil or excessive combustion blow-by past worn piston rings.
310T Preventive Maintenance and Inspection 4
During a pre-trip inspection, a technician notices the steering wheel has more than 2 inches of free play on a vehicle with a 20-inch steering wheel.
What action is required?