how to check vacuum leaks

my w107 350 slc with 3,5 L V8 motor 116982 has a fluctuating idle when the engine is cold. usually this problem stems from old AAV. I had my aav overhauled recently. the problem continues to a lesser extent.
how can I check If there is any leakage in the system

...would be nice, if you could use something like "hello" or your name in this Forum, maybe then is someone willing to help you !?!

Greets
Christian

Hi Juan,

there are 2 possibilities:

1. Use brek cleaner and spray on areas where you assume leakage. If rpm changes then, you found it. However you have to assure that brake cleaner is not sucked into open throttle after removing air filter.
2. Better method is to use a smoke machine and press smoke into manifold area. Then you can easily see where it escapes and notice the leakage. We use this method during our workshops. Check thread "Nebel des Grauens" or ask user Messerflo in Sternzeit for construction of such a machine.

Best regards to Istanbul!

Hi Christian,

Sorry You are right.

Greetings,
Juan

Hi Volker,

The thread Nebel des Grauens gives detailed information. Thank you for the support.

Best Regards,
Juan