Text and photos by Mike Mavrigian
Smoke machines have quickly gained increased popularity among shop techs as ideal leak detection devices, applicable to vacuum systems, EVAP systems, cooling systems, oil systems, and even locating wind/water leaks at glass and body panels.
This review covers the features and operation of one specific unit, the Smoke Wizard Model GLD-50 diagnostic smoke vapor machine, manufactured by Global Leak Detection Corp.
First things first
Before using the smoke machine for the first time, pour the entire contents of one 8-oz. UltraTraceUV solution (provided) into the smoke chamber through the dipstick tube port located on top of the unit. Verify correct level and re-install the dipstick. According to the maker, one bottle will perform more than 200 cycle tests.
Install the air fitting into the inlet port located on the top handle, opposite the outlet hose. As with installing any NPT air fitting, apply a bit of thread sealant to the fitting threads prior to installation (Teflon tape or paste).
Install the supplied hanger hook. This threads into the top of the carry handle (thread size 10x32). By the way, the hanger hook is made of stainless steel and is covered with a clear vinyl tube to prevent marring painted finishes.
The GLD-50 kit includes the following:
* Cap plugs kit GLD005 (for sealing systems under test).
* Smoke diffuser GLD006 (adapter designed to locate leaks around doors, windows, sunroofs, trunks, etc.).
* Adapter cone GLD007 (for introducing smoke into the intake system, exhaust system or into any orifice that accommodates the cone size).
* Combination light GLD043K that delivers a white light for easier smoke location, an ultraviolet light (UV) that highlights the fluorescent dye that is deposited at the exact leak location, as well as a red laser light for easier pinpoint accuracy.
* EVAP service port adapter GLD003.
* EVAP service port Schrader valve removal/install tool GLD004 (note that the Schrader valve features a left-hand thread: turn clockwise to remove).
* Air fitting GLD014 (two fittings are supplied, including the automotive style fitting (GLD013) as well as an industrial fitting provided if needed.
The smoke solution
The solution provided in the kit is not a generic mineral oil, such as baby oil. According to the manufacturer, the patented UltraTraceUV solution is OEM-approved and will not void any vehicle factory warranties. Unlike generic mineral oil, the UltraTraceUV features a trace dye that marks the exact location of a leak, increasing diagnostic accuracy. Global does not recommend the use of baby oil, citing potential damage to vehicle systems.
Using the Smoke Wizard
Operation is fairly simple. For general-purpose leak testing, connect shop air to the unit’s air inlet fitting. The shop compressor should be regulated to 75 to 125 psi. The unit is designed to handle a maximum inlet pressure of 150 psi. For safer EVAP system testing, don’t use shop air. Instead, connect the unit to a supply of inert gas, such as nitrogen or CO2.
Hang the Smoke Wizard (using the hanger hook) from a convenient location (underside of hood). Note that OEM hood props are designed to support the weight of the hood alone. Just to be safe, if you hang the unit from the hood, it’s a good idea to add a back-up prop rod for additional hood support.
Connect the unit’s red alligator clip to 12V DC power (battery positive) and connect the black clip to chassis ground. At this point, the unit’s green battery light will illuminate (FYI: A blinking green light indicates a weak battery or poor connection).
If you’re testing for engine vacuum/induction leaks, use the included black cone to access the intake system (air inlet snorkel, etc.), and connect the unit’s smoke supply hose to the cone. If testing for exhaust leaks, you can insert the cone into the tailpipe.
For EVAP testing, use the supplied adapter GLD003 on vehicles with a factory EVAP service port (remove the Schrader valve from the EVAP service port to connect the adapter). For vehicles that don’t feature a factory EVAP service port, install the fuel cap adapter GLD034 or GLD036 (not supplied but available separately) and connect the smoke supply hose.
Once you’re “hooked up,” press the unit’s ON button. The red light illuminates, indicating smoke production for five minutes (the unit is timed for five minutes). Move the unit’s flow control valve to the full-open position (pointer facing the largest white dot) in order to deliver maximum smoke. Once the system is full of smoke, reduce the smoke volume a bit (this will help to locate the source of the leak).
You may use the white light to aid in locating the source of the leak. Or you can use the UV light (along with wearing yellow glasses) to locate the dye trace (the longer the smoke is allowed to exit, the more dye will be deposited at the leak location).
Checking for wind and water leaks
If the customer complains about an annoying wind noise or water leak (windshield, doors, trunk gap, etc.), set the vehicle’s climate control to “Fresh Air” (not to re-circulate), and set the blower on full-speed. This creates positive cabin pressure.
Connect the tester’s supply hose nozzle to the supplied Smoke Diffuser. Lay smoke along the suspected path of leaks (along seal areas). Look for smoke disturbance, which will indicate a leak (smoke will kick out as a result of cabin pressure).
My brief test
During my loan period of the GLD-50, I filled the smoke solution well with an entire 8-oz. bottle of UltraTraceUV solution. After connecting the pressure port to my shop’s compressed air, I connected the unit’s alligator clips to a known weak battery, and as described in the unit’s manual, the green battery light blinked.
I then connected power to a known fully charged battery and obtained a constant green indicator light. As soon as I depressed the pressure-sensitive “smoke on” switch, the red light illuminated and smoke began exiting the smoke hose (accompanied by a light gurgling noise).
As expected, the smoke production stopped at the five-minute mark (as previously noted, the unit is timed to shut down after five minutes). At any time during smoke operation, simply depressing the power switch instantly turns the unit off.
The smoke (under natural and shop florescent light) is whitish in color and produces a pleasant sweet-perfume odor). The smoke also has a notable “hang time,” and doesn’t disappear quickly, which helps to locate leaks.
I also played with the flow control (which only affects smoke volume output, not pressure). I started out at full-flow, and then dialed-down. In confined/crowded engine bay areas, reducing flow definitely helped to pinpoint leaks.
While working with the unit, I connected to a 1999 Camaro and to a 1977 Datsun 280Z. Using the cone adapter, I sent smoke into the Camaro’s intake duct and quickly found a vacuum leak (dried out/cracked rubber fitting) at the right side of the intake manifold.
Even without using the white/UV flashlight, the small leak was readily visible as a wispy trail of smoke. Using the UV light and yellow glasses, this leak was even more apparent. On the Datsun Z engine, I introduced smoke to the carbon canister vacuum line and quickly discovered a mistakenly disconnected vacuum line at the base of the distributor.
The unit is very simple to use and offers a multitude of leak-locating diagnostic possibilities.
Model GLD-50 specifications
Height (less hanger hook) = 10 in.
Length = 5 in.
Width = 8.5 in.
Weight = 7 lb.
Shipping weight = 11 lbs.
Power consumption = 12 V DC
Solution max. volume = 8 oz.
Supply pressure = 13 in. HzO (0.032 bar)
Supply volume = 10 liters per minute
Smoke supply line = 10 ft.
Power supply line = 10 ft.
Power supply = 15 amps
Additional model perfect for EVAP testing
Another available unit is GLD-40, which performs all of the functions of GLD-50, plus offering pressure and vacuum EVAP monitoring/testing. This allows you to monitor EVAP system pressure or vacuum while comparing to fuel tank pressure sensor scan data, to provide even quicker and more accurate diagnosis. The unit features a very handy built-in graduated tube that allows you to monitor pressure or vacuum decay as well.
By the way, the GLD-40 is available in your choice of colors (yellow, black, silver, purple, green or red), in case you prefer to color-coordinate with your shop color.
Global Leak Detection Corp.
Tech support: (866) 670-7734
M-F, 8:30 a.m. to 4 p.m., Pacific time)