A gasoline engine is essentially a big air pump. You know, it sucks in air, it combusts fuel and then expels it through the exhaust. And in this process of acting like a big pump, it creates a vacuum in the intake. And the vacuum source on a car can give you a good indication of the health of the engine. A good steady vacuum of 18 to 21 inches of mercury will indicate that you have a good solid motor. While other indications might tell you something's wrong. So with this car, you know, we kind of had a little bit of trouble with the braking. And because our hydrovac unit on our braking system is operated by vacuum, we're actually going to start checking the braking system by actually doing a vacuum check. We've got our vacuum hoses and our vacuum gauge hooked up. What we did is we actually drew our vacuum off the hydrovac power brake booster. That is a good source of vacuum. So we know we'll be getting a good test reading here with the gauge. After we got that hooked up, we then did a visual inspection of all the hoses and plugs on the carburetor and any other possible sources of a vacuum leak. And you know, with a good visual inspection, you'll see right away if you have any issues. The next thing we can do then is start the engine and see what our numbers are. Go ahead and start her up. Very good. Check her down. Okay, as you can see, we had a good solid 19 to 20 inches of mercury. Right where we want to be. Even though this motor has got 100,000 miles on it, never been opened up, never touched, pulling good vacuum, good solid motor. So we shouldn't have any problem with our braking system. And we know that we've got a good source of vacuum for that. The vacuum system in a car can tell you a wealth of things about how the engine is, whether your timing is late, to advanced, if you have sticky or burnt valves. I've put together a chart that shows you know, basically what each of the readings indicate. You can get that at classiccarrestorationclub.com.