Where is vacuum line?

I want to use Sea Foam engine cleaner on my 1990 Honda Accord and it says to slowly pour it into a vacuum line that goes into the manifold. The recommendation is the power brake booster line. I have no idea where this item is or what to look for. Is it easy to get to? Where is it? Thanks

The brake booster is the (normally) black, round metal housing that your brake master cylinder is mounted to. It’s typically bolted to the firewall, right opposite (meaning inside the engine compartment) your brake pedal. The booster line is the rubber hose that runs from it to the engine. It’s normally ~1/2" to 3/4" in diameter.

OK, I will look tonight.

Thanks for your help!

I’ll bet you can find about 20 videos of people doing this on Youtube.

Yep…the brake booster is a MAJOR vacuum line…be CAREFUL pouring that stuff into that line… That line pulls MAJOR vacuum…did I say that already? LOL… But yeah go slow bec you don’t want to start looking up nor asking us what Hydro-lock is and what it can do. PLEASE go slow or use a reducer of some sort to prevent you from sucking up a TON of liquid at one time.