Why Capacitors go bad
The "Bruno" tester I use has one, as do the old "Merc-o-Tronic" testers of which I have two "non working" ones
To my knowledge none of the modern solid state testers have a leakage test. I have a couple of "china" testers which can VERY accurately give you the capacitance value down to very small values, and therefore quite useful. But for automotive caps leakage testers are far and few
The "Bruno" tester I use has one, as do the old "Merc-o-Tronic" testers of which I have two "non working" ones