ASE Practice Test (E1: Truck Equipment Installation & Repair) Flashcards

When installing an upfitter-supplied work body on a cab-chassis, the FIRST step before drilling any holes in the frame is to:

Answer: Consult the chassis manufacturer's body builder guidelines for drilling restrictions

Every chassis manufacturer publishes body builder guidelines specifying where holes may and may not be drilled in the frame, acceptable hole sizes, and spacing requirements. Drilling in restricted areas (near welds, suspension points, or high-stress zones) can weaken the frame and void the warranty.

A hydraulic liftgate is cycling slowly in both raise and lower directions. The MOST likely cause is:

Answer: Contaminated or low hydraulic fluid

Slow operation in both directions indicates a system-wide restriction or insufficient flow. Low or contaminated hydraulic fluid is the most common cause. A faulty solenoid or wiring issue would typically affect only one direction of operation.

When splicing into a chassis OEM wiring harness to power upfitted equipment, the correct method is:

Answer: Use a dedicated relay, circuit breaker, and properly rated wiring from the battery or PDC

Upfitted equipment should always be powered through its own dedicated circuit with a properly rated relay, circuit breaker (not a fuse alone for heavy loads), and wiring sized for the load. Tapping into existing OEM circuits risks overloading them and causing failures or fires.

A utility body's rear compartment doors will not stay latched. The MOST efficient correction is:

Answer: Adjust the striker plate position to achieve proper latch engagement

Door latching problems on utility bodies are most often caused by misalignment between the latch and striker. Adjusting the striker plate to position it within the latch engagement zone is the correct and most efficient first repair step before replacing components.

A PTO (power take-off) driven hydraulic system is making a grinding noise during operation. The MOST likely cause is:

Answer: Low hydraulic fluid level causing cavitation at the pump

Grinding or cavitation noise in a PTO-driven hydraulic system typically indicates the pump is starved of fluid due to a low reservoir level or a restricted inlet line. Cavitation causes the pump to draw in air, producing characteristic grinding and chatter noises and accelerating pump wear.

After installing a flatbed body on a cab-chassis, the completed unit must be weighed because:

Answer: GVWR, front/rear axle ratings, and payload capacity must be verified for legal operation

After installation, the vehicle must be weighed on certified scales to verify that front axle weight, rear axle weight, and total vehicle weight do not exceed GVWR and individual axle ratings (GAWR). Operating an overloaded vehicle is illegal and dangerous, and the chassis ratings limit the payload capacity.