Evaluation and Testing Process Flashcards
7 cards from real 310T practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Evaluation and Testing Process flashcards as text
During a road test evaluation of a Class 8 truck, the technician notices the vehicle pulls to the right when braking. What is the MOST likely cause?
Answer: A seized or dragging brake on the left front axle
A dragging or seized brake on the opposite side of the pull causes unequal braking force, pulling the vehicle toward the stuck brake.
A coach technician is performing a pre-inspection before road testing a bus with a reported rough idle. What should be done FIRST?
Answer: Connect a scan tool to retrieve active fault codes
Retrieving active fault codes first gives direction and prevents overlooking stored diagnostic information before starting other tests.
When using an oscilloscope to evaluate a crankshaft position sensor signal on a diesel engine, a good waveform should show:
Answer: A sine or digital pattern with a missing tooth gap at TDC reference
The crankshaft position sensor produces a pattern with a deliberate missing tooth gap that the ECM uses as a TDC reference point.
A technician is evaluating a hydraulic power steering system on a truck. Steering effort is high at low speeds but normal at highway speeds. The MOST likely cause is:
Answer: A clogged power steering filter or low fluid level
A clogged filter or low fluid restricts flow and pressure, reducing assist most noticeably at low speeds when demand is highest.
During evaluation of a truck's air brake system, the governor cut-in pressure is found to be 95 psi and cut-out is 130 psi. This indicates:
Answer: A governor with an excessively wide pressure band that should be replaced
FMCSA regulations require the pressure differential between cut-in and cut-out to not exceed 25 psi; a 35 psi spread indicates a faulty governor.
When evaluating exhaust back pressure on a diesel engine, a reading of 3.5 inches Hg at rated RPM indicates:
Answer: Normal back pressure within acceptable limits
Most diesel engine manufacturers specify a maximum allowable exhaust back pressure of 3.5 to 4.0 inches Hg, so 3.5 is within normal range.
A technician is evaluating the coolant system on a coach and finds the pressure cap releases at 12 psi on a system rated for 15 psi. What should be done?
Answer: Replace the pressure cap as it is releasing below rated pressure
A pressure cap releasing below its rated pressure reduces the coolant boiling point and can cause overheating; the cap must be replaced.