General Tools and Instruments RLD400 - Manual (Page 7)

The reading reflects the concentration of refrigerant gas sensed. The maximum value
will be displayed when the tip of the probe is at the source of the leak. Try switching
between different sensitivity levels while moving the probe until the highest number
appears.
To raise the sensitivity level, press the SENS. button once; this will light the red LED
labeled HI. To lower the sensitivity level, press the SENS. button again; this will light the
yellow LED labeled LO.
The table below can be used to approximate the size of a leak.
Maximum Value Leak Size (oz./yr)
Displayed
1 to 3 < 0.1
4 to 6 0.1 to 0.5
7 to 9 >0.5
Note re: Cross sensitivity to automotive chemicals
Some automotive solvents and chemicals have hydrocarbon properties similar to R134a
and therefore may produce a non-zero reading on the digital leak detector. Before
checking for refrigerant leaks, clean up any chemicals in the list below, which may
produce a positive response.
Brand/type Response
Rain-X windshield washer fluid Y
Ford spot remover (wet) Y
Ford rust inhibitor Y
Ford gasket adhesive (wet) Y
Loctite Natural Blue degreaser (diluted) Y
Ford brake parts cleaner Y
Ford silicone rubber (uncured) Y
Motorcraft antifreeze heated to 160°F Y
Gunk liquid wrench Y
Ford pumice lotion (with solvent) Y
Ford Motorcraft brake fluid Y
Ford carburetor cleaner Y
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