ASE's own T-series study guide is one free PDF that covers all eight tests, with a spec table, a task list and sample questions for each. This page adds what the PDF leaves to you: which content areas carry the most scored questions, the federal rules several truck tests share, and an order for the seven Master tests.
Read it with two corrections in mind. Its introduction says "T1-T9"; there are eight tests. And T3's percentages add up to 102% because of rounding, so count questions, not percent.
Commercial T-series books and courses exist. Check any of them against the task list before you buy, because the list is what the test is written from. Study guides for the other ASE tests: ASE study guides.
Where the scored questions are
Checked Oct 23, 2026 against each source linked in the table. The largest content area of each test. Full splits are on each test's page.
Fact
Detail
Source
Checked
Scored questions
40 to 55 scored questions per test: T3 and T7 40, T2 55, the other five 50
Four areas stand out: air brakes on T4, the A/C system on T7, frame and chassis on T8 and the fuel system on T2. If you are working toward Master, those four are where an extra week of study reaches the most scored questions. Then go back to the smallest areas only to the depth of their task list.
Federal rules the truck tests lean on
The T4, T5 and T8 task lists include inspecting against federal limits. The ones worth knowing by number:
Low-air warning:FMVSS 121 requires a warning below 60 psi. Section 393.51 holds trucks built since March 1, 1975 to that standard; its "55 psi or half of governor cut-out" applies to power units FMVSS 121 did not cover when they were built.
Brake lining and pushrod stroke: both set in 393.47; the numbers are on the T4 page.
Tread depth (393.75): 4/32 in on front tires, 2/32 in on the others.
Steering lash (393.209): set by wheel size and steering type; on a 20-in wheel, 2-1/2 in manual or 5-1/4 in power.
Inspection records: every Appendix A component inspected at least once in 12 months (396.17), the report kept 14 months (396.21), the driver vehicle inspection report kept 3 months (396.11).
Refrigerant: passing T7 does not meet EPA Section 609; ASE’s separate Refrigerant Recovery and Recycling Review and Quiz does.
The Commercial Vehicle Safety Alliance (CVSA) out-of-service criteria are a separate roadside standard with their own thresholds. A question that names a standard is keyed to that standard. Rule text checked on eCFR on Oct 23, 2026.
Questions to try
0 of 2 answered · 0 correct
Question 1 of 2 · T5 Suspension and Steering · 50 itemsNot answered
A crack is found in the bottom flange of a heat-treated steel frame rail. The manufacturer-recommended permanent repair is to:
Explanation
Incorrect: Heating and straightening destroys the heat treatment of the area, and is never approved for a heat-treated rail.
Incorrect: Welding and fish-plating a heat-treated rail leaves a weak, heat-affected zone, so at most it is a temporary repair.
Incorrect: A stop hole only slows a crack and does not restore strength, so it is not a permanent repair.
Correct: Welding heat ruins the heat treatment of the rail around the weld, so the manufacturer's permanent repair is to replace the rail.
Question 2 of 2 · T6 Electrical/Electronic Systems · 50 itemsNot answered
With the key on and the engine cold, a medium-duty truck's electric cooling fan runs constantly. Scan data shows engine coolant temperature as -40 °F. This indicates:
Explanation
Correct: −40 °F is the coldest the module can read, which happens when the sensor circuit is open; the module then runs the fan as a fail-safe.
Incorrect: Welded relay contacts would run the fan, but they would not make the scan tool read −40 °F.
Incorrect: A signal shorted to ground reads extremely hot, not −40 °F.
Incorrect: A thermostat stuck open makes the engine warm up slowly, but the reading would track real temperature, not show −40 °F.
Answer every question to see your score
An order for the Master tests
T4, T5 and T3, in whichever order matches your shop work. They teach the systems that T8 later inspects.
T6, then T2. T2 has 4 starting and charging questions too, so the electrical test first helps if wiring is your weak side.
T7 stands apart: the A/C system is 20 of its 40 scored questions.
T8 last. Its frame and chassis area, 22 scored questions, inspects the brakes, drivetrain, steering and suspension of the earlier tests.
Add T1 only if you service gasoline trucks; it is outside Master. Group tests you are ready for into one order to pay one registration fee, as the cost page shows.
Yes: one free PDF covers all eight tests. Download it from ase.com.
Do I need a separate guide for each T test?
No. The one official PDF covers T1 through T8, each with its own spec table, task list and samples.
What should I study first for the T tests?
The largest content area of the test you are booking: air brakes for T4, the A/C system for T7, frame and chassis for T8, the fuel system for T2. See the weights table.