Vehicle Construction and Parts Flashcards

An estimator is inspecting a bumper cover and cannot find an SAE identification code. They perform an abrasion test on a hidden area of the part, and the material produces a powder rather than smearing. Based on this test, what type of plastic is the bumper cover most likely made from, and what is the implication for its repair?

Answer: Thermoset; it can be repaired with a flexible two-part epoxy/adhesive.

The abrasion test resulting in a powder indicates the material is a thermoset plastic. Thermoset plastics do not melt when heated, unlike thermoplastics which would smear. Therefore, they are typically repaired using flexible two-part adhesives or epoxies designed for this type of material.

A vehicle's radiator core support has been moderately damaged in a front-end collision. Which of the following best describes the primary functions of this component, beyond simply holding the radiator?

Answer: It aligns the front fenders and hood latch, and provides mounting points for headlights and the A/C condenser.

The radiator core support is a critical structural component at the front of the vehicle. In addition to securing the radiator, it serves as a key mounting point for headlights, the A/C condenser, cooling fans, and the hood latch mechanism. It also plays a crucial role in aligning the front-end sheet metal, including the fenders.

Which of the following vehicle systems is considered an 'active' safety system, as opposed to a 'passive' one?

Answer: Automatic Emergency Braking (AEB)

Active safety systems work to prevent a collision from occurring in the first place. Automatic Emergency Braking (AEB) is an active system because it can automatically intervene and apply the brakes to avoid or mitigate a crash. Seatbelts, airbags, and crumple zones are passive systems because they deploy or function during a collision to protect occupants, but do not take action to prevent it.

An estimator is assessing damage to a B-pillar and identifies it as being constructed from press-hardened steel (PHS), also known as Boron steel. According to most manufacturer repair guidelines, what is the generally accepted repair method for this component?

Answer: Repair is not recommended; the part must be replaced at factory seams.

Press-hardened steels (PHS) and other Ultra-High-Strength Steels (UHSS) get their strength from a specific heat-treating and cooling process. Applying heat for straightening or welding in a non-approved sectioning area can compromise the molecular structure and safety of the part. Therefore, manufacturer guidelines almost universally state that these components should not be repaired or sectioned but must be replaced at factory-designated seams.

In a unibody vehicle, the front frame rails are designed with specific indentations and shapes along their length. What is the primary purpose of these engineered features?

Answer: To control and absorb energy by collapsing in a predetermined manner during a collision.

The indentations, holes, and specific shapes engineered into unibody frame rails are designed to create 'crush zones' or 'crumple zones'. These zones are intended to fold and collapse in a controlled way during a front-end impact, absorbing collision energy and preventing it from transferring to the passenger compartment.

A technician is assessing a frame rail on a heavy-duty truck and notes it was manufactured using a hydroforming process. What is a key characteristic of a hydroformed rail that an estimator must consider when planning a repair?

Answer: They typically have variable thickness and complex, seamless shapes, often requiring specific sectioning procedures or full replacement.

Hydroforming uses high-pressure fluid to shape metal into complex and strong, yet lightweight, single pieces. This results in seamless components that can have varying thickness and shape. Due to this complex construction, repair options are often limited, and manufacturers provide very specific sectioning procedures, if any are allowed at all. Damage beyond specified areas typically requires full part replacement.