ujhonda

There are many methods you can use to locate vacuum or exhaust
leaks, but one of my favorites is to use a modified stethoscope
to listen for the source of the leak. Most parts supply stores
sell a mechanics stethoscope for about 15 dollars. It is similar
in construction as the kind doctors use except a metal rod is
attached to the bell so that you can probe for taping, ticking or
knocking sounds in the engine. The bell is attached to the ear
pieces with rubber tubing and can be removed. If you remove the
bell and attach a two or three foot length of copper tubing in
it's place, you will have the perfect device for tracking down
vacuum or exhaust leaks. Even the tinniest vacuum leak makes a
hissing sound and sometimes it is impossible to tell where it is
coming from, but if you probe along all the suspected areas you
will be able to track the leak down as it gets louder and louder
the closer you get to it with the tubing probe on your modified
stethoscope. You can bend the copper tubing to reach around
corners and get to hard to reach places.
A word of caution though! You should drill or cut a small hole a
few inches back from the end of the copper tubing. This will
prevent accidentally sucking your ear drum out in the event that
you should happen to place the end of the tubing directly over an
open vacuum port.
I have successfully used this device to locate some really hard
to find vacuum leaks in some unlikely places such as around fuel
injectors and carburetor base gaskets.
If you can't get a mechanics stethoscope to use for making this
device you can build a make shift one from some rubber hose and a
piece of metal tubing. Just hold one end of the hose up to your
ear and probe around with the tubing that is attached to the
other end of the hose.
Happy hunting.

I found this on the net, now I think I can find my exhaust leak


Modified by ujhonda at 5:09 PM 11/16/2006