Kentucky CDL Combination study plan

Define each of the three combination-vehicle braking systems (service, parking, emergency) and state which axles they act on

List the five coupling steps in order and the five uncoupling steps in order from memory with no notes

Identify the three points of contact you maintain when climbing into or out of a tractor cab and explain why facing the vehicle matters

Explain the consequences of a trailer that is too high or too low when coupling, including the visual check of the fifth-wheel jaws after connection

Describe how a tractor protection valve and trailer air supply valve work together during a breakaway

Explain the tug test and the visual jaw check, and state what each one can and cannot detect

Sequence the pre-trip air-loss test for a combination vehicle and state the acceptable leakage rate logic

Identify the specific hazards of coupling on a slope or soft ground and how to mitigate each

Label the components of a dual air brake system and trace the service and emergency circuits from compressor to brake chambers

Explain the low-air warning threshold and the conditions that trigger the spring brakes to apply automatically

Describe the three-part air brake check (static leak, applied leak, low-air warning) in the order a tester would perform it

Distinguish supply pressure from delivery pressure and explain why a gauge reading alone does not prove the brakes work

Explain how brake fade develops on a long downgrade and list the correct control actions in order

Describe proper downhill speed selection and the role of engine braking and gearing on a combination vehicle

Identify the signs of an air leak severe enough to stop driving and state the response

Explain how trailer brake timing and pushrod stroke relate to stopping distance on a combination

Explain what ABS does and does not change about normal braking technique on a combination vehicle

Describe what the ABS malfunction lamp means and what changes in your driving when it stays on

Explain how ABS interacts with the trailer supply line and why losing trailer ABS does not necessarily mean losing trailer brakes

Describe the correct response to a drive-axle skid versus a trailer-axle skid and why steering input matters

Build a complete combination pre-trip inspection sequence covering tractor, trailer, coupling, and air systems

Explain offtracking and state how rearward amplification and trailer length change the path the rear wheels take

Describe the correct setup and execution of a right turn and a left turn with a long trailer, including mirror use

Explain why backing a combination requires GOAL and how to correct a trailer that is drifting in the wrong direction

Explain the purpose and correct hookup of a converter dolly, including the air line and electrical connections

Describe the specific hazards of pulling multiple trailers and how to manage them

Explain how center of gravity and load placement affect rollover risk on a combination vehicle

Describe the correct action when a trailer starts to roll over versus when it starts to skid, and why the responses differ

Re-score every prior self-quiz and retake any domain below 80%

Perform a full timed mock knowledge test across all nine domains without notes

Re-explain coupling, the air brake check, and ABS malfunction response aloud with no reference material

Identify your two weakest domains and write a targeted review list for each