What are the symptoms of a leaking vacuum chamber and what's the easiest way to check it. Surely, you don't have to remove the alternator and pwr. steering pump to get at it?

 

There are a couple of chambers in the FD. If one is leaking it may show on your boost gauge at idle. Vacuum should be at least 16# for a stock 7.

Usually a leak in the chamber won't affect boost TOO much. I had one hose completely off of the vaccuum chamber (one on top of the engine with two hoses coming out of it) and I was still gettting the 10 - 8 - 10 pattern.

 

i'm curious...@ stop idle i get 15-16 vacuum. But while cruissing i get 20 there. Does this mean i have some kind of vacuum leak. I am experiencing low boost patterns during secondaries.

 

if you think the chamber is leaking just run the engine for a couple of minutes then turn it off.

Then pull one of the hoses off the vacuum chamber. If you hear it pop or suck in air then it is holding. You can also put a vacuum gauge/tester on it and pump it down. Let it sit and see what the gauge reads after a few minutes. You can also check the check valves like this. If you are running the factory hoses don't be suprised to find vacuum leaks all over.