Like a compression test, a leak down test is accomplished by replacing a spark plug with the tester hose. Learn the differences between leak down test and compression test, including principles, procedures, and when to use each for accurate engine diagnosis. Compression test is normally used to determine (partial) condition of engine
How To Use A Leak Down Tester at Christopher Hurtado blog
Leak down test is normally used to determine what's the fault with engine but it will also give you leak down number that can be used to determine (the same partial) condition of the engine.
Learn why they matter for auto mechanic students.
