Vacuum Leaks

[scott.john.mockry@bangate1.tek.com]

Another way to track down vacuum leaks is to use a set of pliers that allow you to 
pinch off the various vacuum hoses connected to the intake manifold that go inside the car
and to other systems,ie the evaporative canistor etc while the car is running. 
You may want to disconnect the O2 sensor during the test and when you pinch off 
the hose, see if the engine runs radically different. KD tools sells a pair of pliers 
with smooth jaws that have a locking ratchet  designed for this purpose. These pliers 
also work well at pinching off heater or radiator hoses to prevent loss of coolant 
during the replacement of cooling system components.

Some of the repair shops have a new system called "Vacutec" that you connect to one 
of the intake manifold connections and it pumps  into the engine and all the vacuum hoses
an inert white gas (smoke) that tends to come out of any leaks in the system. I saw the system
demonstrated at a tool fair some time ago and it really does work! It makes it easy
to spot vacuum leaks. Of course, it likely costs an arm and a leg.

I have seen  a few technicians use water from the end of a garden hose to find vacuum 
leaks, of course with a large vacuum leak you run the risk of hydrolocking the engine 
as it trys to compress that gulp of H20. Using carb cleaner or starting fluid for finding
leaks is a little tricky as many times the engine will suck the fumes into the normal 
air intake as you spray that stuff around and will make you think you found the 
leak as the engine speeds up after inhaling the fumes. This is really a problem with
carburated engines of long ago......

Scott M.