13.2 T8 Cab and Hood PMI

13.2 T8 Cab and Hood PMI

Exam Focus: ASE T8 Area B (Cab and Hood) is about 5 scored questions / 10% of the 50-question T8 exam. The section is small but safety-dense. Items test whether you inspect hood latches and supports, cab mounts, glass and mirrors, seats and seat belts, wipers, basic HVAC function, and steps/handholds with a PMI pass/fail mindset—not body-shop refinishing theory.

Drivers enter and exit the cab dozens of times per shift. A hood that slams shut, a mirror that will not hold aim, or a broken grab handle creates injury and crash risk. Area B answers almost always prefer secure, functional, and documented conditions over “still drives fine.”

Cab Structure and Mounts

Cab mounts and body fasteners (inspection level)

Class 7–8 conventional and cab-over designs use rubber mounts, spring mounts, or hydraulic cab dampers depending on OEM. At PMI:

• Look for collapsed, cracked, or oil-soaked mount rubber.
• Check for broken bolts, elongated holes, and cab lean relative to the frame.
• Note metal-to-metal contact, clunks when rocking the cab, or visible shift after severe service.
• On tilt cabs (COE and some vocational), verify tilt latches, safety hooks, and hydraulic tilt components per OEM PM—never work under an unsecured tilted cab.

Cab mount failure is not only comfort: misalignment stresses radiator piping, steering shafts, and electrical transitions at the firewall.

Doors, latches, and seals

A door that only holds on the first click is a safety defect—adjust/repair, do not release as “OK if you slam it.”

Hood Systems and Safety

Latches and cables

Conventional hoods typically use two side latches plus a safety catch. Inspect:

1. Latch engagement on both sides—uneven latching twists the hood and can allow partial open at speed.
2. Release cable operation from the cab (where equipped) without excessive free play or frayed cable.
3. Safety catch that still requires a second action to fully open.
4. Hood-to-cowl alignment and missing buffers that cause paint wear or vibration.

Driving with a hood not fully latched is an extreme hazard (hood fly-up). PMI must verify latches, not assume.

Torsion bars, springs, dampers, and props

Hoods are heavy. Assist devices fail:

• Broken torsion bars / weak springs — hood falls rapidly when past center; injury risk.
• Gas struts (on some applications) — weak hold; hood drops.
• Safety cables or hood props — must be present and used; frayed cables are reject items.

Shop rule that ASE respects: never put your head under a hood held only by a weak strut or by balance alone. Use the designed prop/cable and verify condition during PM.

Hood condition

Cracks at latch mounts, broken grille supports that allow debris into the fan, and missing splash shields that expose belts to water/slush are documentable PM findings. Fiberglass/composite hood damage at hinges needs flagging before a roadside failure.

Glass, Mirrors, and Visibility

Windshield and windows

Inspect for:

• Cracks, stars, and chips—especially in the driver’s critical vision area (exact legal zones vary by jurisdiction; PMI thinking is that vision-obstructing damage is not cosmetic).
• Delamination or clouding that blocks view.
• Inoperative or missing sun visors when they affect glare control (function check).
• Side windows that will not close (security and weather; also exhaust infiltration risk in some conditions).

Mirrors

Medium/heavy trucks rely on west-coast, fender, and convex mirrors (configurations vary).

Mirror brackets bent from dock damage are common vocational findings—secure and aim, do not ignore.

Seats, Belts, and Occupant Safety

Seats

• Mounting bolts present and tight; air-seat bags not ruptured; suspension seat locks function.
• Adjustment levers work; seat does not free-slide on tracks under load.
• Severe foam failure or exposed frames that prevent proper belt geometry—document.

Seat belts

Seat belts are not optional comfort trim:

1. Webbing free of cuts, chemical burns, and severe fray.
2. Latch plates and buckles engage and release correctly.
3. Retractors take up slack; locks function when jerked (per safe test method).
4. Anchor bolts present; no sheet-metal pull-through.
5. Passenger and sleeper restraints (where part of the unit’s required equipment) included in PM scope as applicable.

Any non-functional driver seat belt is a hard safety fail for release thinking on T8-style PMI questions.

HVAC Function Check (PM Level)

T7 covers deep A/C diagnosis; T8 Area B expects a function screen:

• Blower operates on speeds available.
• Mode control moves air to face/floor/defrost reasonably.
• Heat becomes warm after engine temperature rise (links to coolant level—cross-check Area A if no heat and coolant low).
• A/C clutch engages and air cools if ambient and system allow a basic check (not a full gauge performance test every PM unless fleet requires it).
• Cabin filter service if equipped and due.
• Unusual odors: sweet (coolant/heater core), musty (drain/evaporator)—document.

Defrost capability matters for legal operation in weather; a dead blower in winter is more than comfort.

Wipers, Washers, and Dash Visibility Aids

Inoperative wipers in conditions requiring them are classic out-of-service risk items in enforcement thinking—treat PM discovery of dead wipers as repair before release, not “next time.”

Also verify that required dashboard lamps prove-out (see Area C) and that instruments are visible—not blocked by illegal decals in the critical view.

Steps, Deck Plates, Handholds, and Cab Access

Slips and falls are a major industry injury category. PMI must include:

• Steps and stirrups — secure, not bent into tire path, grip surface usable (not completely worn smooth or packed with ice/grease without cleaning).
• Deck plates / catwalks behind cab — secure fasteners, no large holes, non-slip surface intact enough to use.
• Handholds / grab handles — present on cab and where OEM designed; cracked welds on grab rails are reject.
• Battery box steps (if used for access) — covers latched so they do not open underfoot incorrectly.

Missing third-point-of-contact hardware after body damage is a frequent write-up: restore access equipment, do not tell drivers to “just jump.”

Fire Extinguisher, Triangles, and In-Cab Equipment (Awareness)

Many fleets include in the cab PM:

• Extinguisher present, charged, mounted.
• Warning triangles present.
• Spare fuses/load secure (not rattling into pedals).
• Horn function (electric/air as equipped).

Exact regulatory inventories vary; ASE-style questions emphasize presence and basic function of safety equipment the stem describes as required for that vehicle’s operation.

Sleeper and Interior Condition (High Level)

On sleepers: bunk restraints if required by design, no open wiring from driver-added equipment that creates fire risk, and no unsecured heavy objects that become projectiles. Aftermarket inverter installs with poor cabling should be flagged (ties to electrical PMI).

Cab/Hood PMI Sequence

1. Approach: overall cab lean, panel damage, hood alignment.
2. Hood closed: latch security both sides; safety catch.
3. Open hood with proper prop/cable; inspect assist devices and underhood visibility items as part of engine PM handoff.
4. Cab mounts/doors/seals.
5. Glass and all mirrors.
6. Interior: seats, belts, pedals clear, horn, wipers/washers, HVAC function, obvious dash warnings.
7. Exterior access: steps, handholds, deck plates.
8. Safety equipment inventory per fleet form.
9. Document defects; classify safety-critical vs cosmetic.
10. Close-out: hood fully latched, doors latched, tools removed from cab steps.

Common Area B Traps

Exam Strategy for Area B

With only ~5 questions, each miss hurts. Prefer answers that secure the hood, restore three-point access, reject non-functional belts, fix vision equipment, and verify latches fully engage. Connect HVAC “no heat” back to coolant inspection when the stem invites it. Treat cab PMI as people protection and visibility, not upholstery preference. Master mounts, latches, hood safety, glass/mirrors, restraints, wipers, basic climate function, and steps/handholds, and Area B becomes reliable points on T8.