Red Seal Transport Trailer Technician flashcards
Red Seal Transport Trailer Technician · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Spring brake caging
- A procedure that mechanically compresses the power spring using a caging bolt so the brakes release without air pressure. Wheels must be chocked first because the parking brake is disabled.
- Lockout/tagout on trailers
- Isolating and de-energizing stored energy sources such as air reservoirs, hydraulic landing gear, and electrical circuits before service, then applying a lock and tag to prevent re-energization.
- Chlorinated brake cleaner hazard
- Chlorinated solvents decompose into phosgene gas when exposed to heat, welding arcs, or hot surfaces. Use non-chlorinated cleaner near welding and ensure ventilation in enclosed areas.
- Torque wrench extension effect
- Adding an adapter or extension in line with the wrench increases effective lever length, so indicated torque differs from actual torque unless the setting is recalculated for the new length.
- Voltage-drop testing
- Measuring voltage lost across a circuit while current flows. Excessive drop on a 12 V trailer circuit, generally above 0.5 V, indicates high resistance in cable, terminal, or ground.
- Micrometer reading method
- Read the barrel graduation for whole millimetres or tenths of an inch, then add the thimble graduation. A metric micrometer thimble reads 0.01 mm per division.
- Dial indicator runout
- Total indicated runout is the difference between the maximum and minimum dial readings as a part rotates. It measures shaft, hub, or flange eccentricity against a specification.
- Galvanic corrosion at joints
- When aluminum and steel touch in the presence of moisture, the aluminum corrodes preferentially. Isolation tape, coated washers, or stainless fasteners separate the dissimilar metals.
- Kingpin setback
- The distance from the trailer nose to the kingpin centre. Increasing setback shifts more trailer weight onto the tractor drive axles and changes turning behaviour.
- Frame crack repair rule
- Cracks running from flange into web must be repaired using the manufacturer's welding procedure and reinforcement design. Field-bolted doubler plates are not an approved structural repair.
- Thrust angle misalignment
- The angle between the axle centreline and the trailer centreline. Misalignment causes tire scrub and irregular wear, and is corrected by shimming or bending within the axle maker's limit.
- Height control valve function
- A valve that senses suspension ride height and adds or exhausts air to maintain the set height. Incorrect adjustment changes axle load split and driveline angle.
- Plugged axle vent effect
- A blocked axle vent lets pressure build inside the housing as it warms, forcing lubricant past the wheel seals. Replacing the seal without clearing the vent causes a repeat leak.
- Slider pin engagement
- Tandem slider lock pins must be fully seated in the frame rail holes before the trailer moves. Partial engagement allows the axle group to shift under braking or load.
- Brake chamber pushrod stroke
- The distance the pushrod extends when the brakes are applied. It is measured at the chamber and compared with the limit for that chamber type and slack adjuster length.
- Automatic slack adjuster diagnosis
- An automatic slack adjuster that will not maintain adjustment usually indicates a foundation brake problem such as a worn cam, drum, or shoe, not a failed adjuster alone.
- Trailer air leak test
- With the system charged and brakes applied, apply soap solution to fittings, valves, and chambers. A steady stream of bubbles indicates a leak that must be repaired.
- ABS lamp self-test
- The trailer ABS lamp should light at key-on and go out after the self-test. A lamp that stays on indicates a fault code stored in the ECU.
- Seven-way connector ground pin
- The white pin is the ground circuit. A poor ground causes dim lamps, cross-feeding between circuits, and false ABS faults, so ground voltage drop is tested first.
- LED flasher compatibility
- LED lamps draw less current than incandescent, so an old thermal flasher may not cycle. A load resistor or LED-compatible flasher restores correct turn-signal operation.
- Dual tire circumference match
- Paired dual tires should have closely matched circumference, typically within about 6 mm of tread depth difference, so the larger tire does not carry most of the load.
- Cold tire inflation check
- Tire pressure is set and checked cold, before the tire has run. A warm tire reads higher and should not be bled down to the cold specification.
- Wheel nut re-torque
- Wheel nuts are tightened in a star pattern to specification and rechecked after the first 50 to 100 miles. Loose or over-torqued nuts can cause stud failure or wheel loss.
- Hub bearing end play
- Axial movement of the hub assembly measured with a dial indicator. Excessive play or a leaking seal requires bearing inspection, repacking, or replacement.
- Fifth wheel pull test
- After coupling, apply tractor power against the locked trailer brakes and confirm the trailer does not move. This verifies the jaw has closed around the kingpin.
- Gladhand colour code
- The service or control air line is typically blue and the emergency or supply line is red. Crossed lines cause trailer brakes to apply or fail to release.
- Landing gear leg inspection
- Check the leg for bending, the gearbox for lubrication, the crank for damage, and the foot for wear. A leg that will not raise may have a stripped gear or bent screw.
- Breakaway valve function
- A valve that applies the trailer brakes if the trailer separates from the tractor. It must be connected to the tractor by a lanyard or cable rated for the application.
- Reefer refrigerant recovery
- Refrigerant must be recovered, the system evacuated, and leak tested before charging. Handling requires certification, and the specified refrigerant and oil must be used.
- Liftgate drift diagnosis
- A liftgate that drifts down under load usually has a leaking check valve or a failed cylinder seal. Verify relief valve setting and fluid level before replacing parts.
- Raised dump bed blocking
- Never work under a raised dump bed supported only by hydraulics. A hose or fitting failure can drop the bed, so use rated blocking or a mechanical safety prop.
- Root-cause repair verification
- Confirm the repair by testing the system after reassembly. A repeated seal leak, for example, may trace to a plugged vent rather than the seal itself.