Lesson 4.6 — Coolant Testing, Refill, and Air Bleeding | ASE A1 Engine Repair

Lesson 4.6 — Coolant Testing, Refill, and Air Bleeding | ASE A1 Engine Repair Coolant is tested, not judged by color: protection and inhibitor condition by strip and refractometer. Drain, flush, and refill with the specified type — and the air bleeding that decides whether the heater works and the thermostat ever sees coolant. ASE A1 tasks covered in this lesson: D11. CHAPTERS 0:00 Title & Overview 0:39 Test strip and refractometer readings 1:26 Two technicians' claims crossed out 2:13 Drain, flush, refill — specified coolant only 3:04 Vacuum fill tool evacuating the system 3:48 Air pocket at a high point: heater core 4:31 Pause And Answer 4:53 Explanation 5:40 Recap Card WORKBOOK Follow along on page M4-6 of the ASE Prep Lab A1 Workbook (printable): follow-along worksheets keyed to every lesson, the full 300-question prep bank with explanations for every answer, and three timed 55-question mock exams. https://www.etsy.com/listing/4605357576 ERRATA — HELP US KEEP THIS ACCURATE Spot an error in this lesson? Report it in the comments. Corrections are pinned on the video, and the workbook errata page is updated first. Built from ASE's published A1 task list. Not affiliated with or endorsed by ASE.