Smoke evaporator testers are used to find and diagnose leaks anywhere on a vehicle. Once you hook the machine up to the intake, the smoke will course through the tubing. If smoke comes out anywhere other than the machine's relief vent, you have found a leak. The machines provide an efficient way to discover problems and allow easy demonstration of the leaks to others. Mechanics at automotive repair shops use professional-grade smoke evaporator tester machines, which cost $800 to $1,000. It is possible to make your own general-purpose smoke machine for much less.
Remove the front plate of the fog machine. Use a screwdriver if necessary. Underneath the plate, you will find a copper tube. Follow the tube until you find a small plastic lip around an opening.
Stretch the vacuum line around the plastic lip. Set the fog machine next to the part of the car you will be testing. Prop the machine up so that the side attached to the vacuum line tilts upward. This will allow the fog juice to flow freely through the line and not become clogged.
Attach the other end of the vacuum line to the part your car that you will be testing. Always make sure that the car is turned off and in park before you do this. To check for leaks in the engine or vacuum systems, insert the vacuum line into a port on the intake of the car. To check for leaks in the brake system, attach the vacuum line to the power brake booster. You also can checks for leaks in the seals around doors and windows by slowly swiping the vacuum line around the seals.
Pour fog juice into the machine. Turn the machine on. Leave it on for only 30 to 60 seconds at a time to avoid overheating the copper tube and vacuum line. Turn the machine off and look for escaping smoke. If you cannot easily see smoke leaking from the car, turn on a flashlight and check again.
