MAHLE RTI ELF-1 - Manual (Page 7)

Page 4
Some systems may have a relief valve that relieves pressure in the system well
under 1 PSI. Volkswagens, for example, relieve at about 0.4 PSI. It may be
necessary to remove the line or pinch it off to seal the system.
Fog will be flowing when the Timer is activated and the Fog Tube is connected to the system. The Flow
Indicator will be illuminated. The actual flow will be displayed on the Flow Meter, and increasing
pressure will be indicated by the Pressure Gauge.
Pressure will reach 1 PSI and the pressure switch will stop any further flow assuming that there is no
leak in the system. The Flow Indicator will go off. Observe the Pressure Gauge to see if the 1 PSI of
pressure is dropping. A leak is indicated if the pressure drops.
If the system can hold this pressure for 3 minutes it can be assumed that there is no leak.
Should there be a leak in the system, the pressure will decrease about 0.20 PSI and the pressure
switch will activate causing ELF-1 to begin applying pressure.
Constant on/off cycling of ELF-1 indicates that a leak is present. The size of the leak can be estimated
by using the Flow Meter, the Pressure Gauge and the Leak Chart on Page 6.
ELF-1 will not shut off automatically if the system never reaches 1 PSI. This indicates that the system
being tested is not filled or the leak is so large that the amount of fog flowing from ELF-1 into the
system can not raise the pressure to 1 PSI.
Further Investigation: Select the 4-15 PSI mode and very slowly increase the
fog flow with the Pressure Regulator. When the Flow
Meter ball stays in one steady position, the current
pressure and air flow indicated can be used to determine
the size of the leak using the Leak Chart.
3 PSI MODE
ELF-1 operates exactly the same in the 3 PSI mode as it does in the 1 PSI
mode. The major difference is that the pressure switch will stop flow at 3 PSI.
The pressure switch resets when the pressure drops to approximately 2.6 PSI. ELF-1 will begin
supplying pressure again once the pressure drops below this value
The 3 PSI mode may be more useful for testing EVAP systems that have established leaks.
The pressure Gauge may occasionally indicate a higher pressure than
selected. This is the result of pressure backing up from the fuel tank and
system flexing. This is not harmful to ELF-1 and may be ignored.