Hmm. I wonder if you're really talking about the vacuum tank or the brake booster.
The vacuum tank is the container that has two hoses connected to it. One hose comes from the intake manifold, where the vacuum is generated by the pistons during the intake stroke. The second hose goes to the brake booster, where the vacuum is used as a brake assist, creating a larger force on the brake cylinders than comes from the foot pedal. It is important to understand that the vacuum is supposed to be a static pressure that, once the vacuum is built up after starting the car, should change only minimally when the brakes are engaged and released. There should be no brake fluid in the vacuum tank. If there is, it can only have come from a failed brake booster.
With respect to testing, I would say that should be easy: Insert a T with a pressure meter and see how long it holds the vacuum. If you want to test the tank by itself, take it out of the car, pressurize it with compressed air and submerge it in water. If you see bubbles (due to a crack), there is something wrong with the tank. However, I think this would be a very rare thing to happen.
If the car is not running smoothly with the hose attached, there is probably brake fluid sucked into cylinders 5 and 6 when starting the car. You may see black fluid being spewed out of the tailpipe.
The vacuum tank is the container that has two hoses connected to it. One hose comes from the intake manifold, where the vacuum is generated by the pistons during the intake stroke. The second hose goes to the brake booster, where the vacuum is used as a brake assist, creating a larger force on the brake cylinders than comes from the foot pedal. It is important to understand that the vacuum is supposed to be a static pressure that, once the vacuum is built up after starting the car, should change only minimally when the brakes are engaged and released. There should be no brake fluid in the vacuum tank. If there is, it can only have come from a failed brake booster.
With respect to testing, I would say that should be easy: Insert a T with a pressure meter and see how long it holds the vacuum. If you want to test the tank by itself, take it out of the car, pressurize it with compressed air and submerge it in water. If you see bubbles (due to a crack), there is something wrong with the tank. However, I think this would be a very rare thing to happen.
If the car is not running smoothly with the hose attached, there is probably brake fluid sucked into cylinders 5 and 6 when starting the car. You may see black fluid being spewed out of the tailpipe.