Vacuum, Exhaust and Interior Air Leak Finder

An easy and inexpensive way to make our own leak finder. I learned this from an old timer mechanic when I was about 10. I've improved his design since then.
1. Pickup a mechanics stethoscope from the Auto parts house or Harbor freight like this.



They cost about $5 and every DIY'r should have one for diagnosing noises.

2. Pickup a 1/8 inch premade brake line about 18 inches long or some kind of 1/4 metal tube.

3. Its very important you add vent holes in the end of the tube. Drill some holes or grind some slots with the edge of a grinding wheel. There needs to be vent holes to release any pressure or vacuum you might get close to. If you don't have them it could cause ear drum damage. I've used my tool hundreds of times safely.



Use it like this.

Use tube to poke around and find wind noises or vacuum noises. It's impossible to miss a vacuum leak when you get close to it. Load hissing sound. Wind noise around windows or doors is very easy to pinpoint.