Yes. Plus, if it were leaking in the engine compartment, I wouldn't hear it so prominently (or at all) in the drivers seat over the sound of the engine.

This brake booster is very old, and sat in the car in the woods for 17 years. When I first started working on it in 2011, I couldn't even move the brake pedal, not even after removing the master cylinder. I kept pushing on it until it started to move, and eventually, through working it back and forth, I got it so I could push the brake pedal in and out easily. I wasn't even expecting it to work, but after replacing all of the brake components and trying it out, it did work, but it has always hissed like in the video.

I'm not even sure it is originally for a '69 Charger; it doesn't look like the A-1 CARDONE Part # 5473501 that all of the parts stores sell:





I want to replace it with a newly rebuilt one regardless; I just want to know which ones are compatible, because some are cheaper than others, especially in terms of the core charge (which I might not even be able to collect, and it is a hassle collecting the core charge via mail order anyway, and you lose some of it when you pay for shipping to return the core).