If you want to find the leak us Ultra-violet dye from NAPA. You pour it in the leaking system, start and idle for a moment to circulate. Get out the black light. Much easier done after dark. I bought a pair of 4' fluorescent black light bulbs for my shop light that I use for this.
There is two formulas water/oil based.
My Lotus Turbo Esprit is the reason I got my lights+dye, it's nickname is the "Exxon Valdez".