Make sure your Smoke Machine has a PRESSURE GAUGE that can verify test pressure, perform decay tests, and verify repairs as explained below. NOTE: Some vapor machines have pressure gauges that measure PSI and not inches of water column.

The Smoke Pro™ Total-Tech™’s very sensitive pressure gauge performs real diagnostics and will do all of the functions described below. Refer to your user’s manual before operating your Smoke Pro® Total-Tech™.

Verify a Safe Test Pressure
With a PRESSURE GAUGE you can prevent over pressurization and possible damage to a sensitive EVAP system. Before you start a smoke cycle, verify safe test pressure by simply putting your thumb over the nozzle (called deadheading) and watch the gauge needle move to the internally fixed output pressure of about 13” water column (less than ½ PSI). This is about the pressure of your breath and is an excellent test pressure for intake, vacuum, and wind and water leaks as well. Don’t trust a smoke machines internally regulated test pressure! Always refer to your PRESSURE GAUGE first!

Note: Of the Smoke Pro® family, only the Smoke Pro Total-Tech™ model has a pressure gauge

Perform Leak Decay Tests
Most technicians are already familiar with the simple process of leak down testing. When pressurizing an EVAP system watch the needle on the PRESSURE GAUGE slowly climb. The difference between the pressures it climbs to and the deadheaded pressure of about 13” is an indication of leak size. If the PRESSURE GAUGE climbs all the way up to the deadheaded pressure (13” H20) and stops close the flow control valve, if the needle does not drop, you verified the system is air tight and that there is no leak. One very important feature is that some times there may be a small leak as indicated by a slow drop on the pressure gauge. If you look over at the flow meter, there is a good chance that this leak will not register on the flow meter as indicated by the ball remaining on the bottom of the flow meter. Remember, a 0.020 leak already shows up near the bottom of the flow meter. This means that by having this PRESSURE GAUGE you can verify the presence of these small leaks. If leaks to small to show up in the limited range of the flow meter ever trip EVAP codes or cause other problems in the future, the Smoke Pro™ Total-Tech will not be obsolete.

We have verified leaks as small as 0.005 and even smaller with the PRESSURE GAUGE using decay and smoke can also be detected in many cases with these size leak standards. A 0.0050 leak is 1/16th the size in area of a 0.020 leak!

Remember, leak decay testing is performed with air only and not during a smoke cycle. The rate of decay varies with different conditions including the amount of empty space in the system you are testing, (the more empty space in the fuel tank, the slower the decay rate), the size of the leak, and possible pressure being created inside the system by outside conditions like hot weather.

Verify a Repair
Smoke machines are fantastic tools because they take the guess work out of making many repairs and of course save lots of time. But did you know that you can verify a repair using the Smoke Pro® Total-Tech’s™ PRESSURE GAUGE? After you’ve located and repaired an EVAP leak you can simply re-pressurize the EVAP system (using air only) with your Smoke Pro® Total-Tech™ and watch the PRESSURE GAUGE climb back up to the 13” and stop. When it stops, close the flow control valve. If the needle does not fall, you can verify that the system is air tight and does not leak. If the pressure falls there is still a leak. It is true that these smaller leaks today will not trigger codes requiring repair but wouldn’t you like to know if leaks are present and determine at your own discretion if a repair is warranted? When emissions standards tighten, the pressure gauge may be your only reference to verify leaks too small to show up on the flowmeter. The Smoke Pro® Total-Tech™ is already compliant with future emissions standards because the pressure gauge will verify ANY size leak.

Ask yourself this question, are cars becoming more complicated and is it possible that smaller leaks in the future will cause problems? The answer is of course YES. Originally 0.040 size EVAP leaks were the required repair. Presently the EVAP leak size to fix in many areas is 0.020 and a leak as small as 0.020 diameter can allow over 30 times the allowable hydrocarbons into the atmosphere then is currently acceptable through the exhaust. Emissions standards are tightening around the country and some say it will be 0.010” soon.

We have been talking a lot about EVAP leaks. EVAP leaks are generally smaller and often will show up in the range of the flow meter. The smaller ones that don’t register in the limited range of the flow meter are of course verified with pressure decay as discussed above. EVAP repairs should however make up only a small percentage of the times you reach for your Smoke Pro™. Most of the repair opportunities will be when a car has a rough idle or stutters at acceleration. Major tune ups are a great time also. These general intake, vacuum or exhaust leaks are usually much larger than the flow meters maximum high range and the flow meter will not be used as a reference during these tests.

Important note: If you “deadhead” the Smoke Pro® Total-Tech™ during or after a smoke test you will likely see the Pressure Gauge’s needle pass your machines normal maximum pressure. This will only happen when you use your thumb and not when you are pressurizing an EVAP system. This erroneous reading is caused by the warmth from the smoke production which happens near the very sensitive pressure gauge. The smoke machines output pressure has not changed from its internally fixed pressure and you have not damaged the smoke machine.

The function of the PRESSURE GAUGE, flowmeter, and other features are explained in just a few minutes on our short and simple video found right here on our website. This simple to understand video is also included free as a DVD with every Smoke Pro®’s accessory kit for quick reference when smoke testing a car. Any tech in any shop can fully understand the hook up and simple functions of the Smoke Pro® with this DVD or website access in minutes. We also include our toll free number and website address on the back of every Smoke Pro®. For a free DVD, just call and ask or email us your info, we will be happy to send you one.