Wigam ELD-H, User Manual

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5 

SAE J1628 RECOMMENDED PROCEDURES 

For the purpose of Automotive A/C Testing with respect to the SAE J1627 standard, the following leak testing 
procedure applies: 

1. Operate 

the 

ELD-H

 in high sensitivity mode. 

2.  Leak test with the engine not in operation. 

3.  The air conditioning system shall be charged with sufficient refrigerant to have a gauge pressure of at 

least 340 kPa when not in operation.  At temperatures below 15

°

C, leaks may not be measurable, since 

this pressure may not be reached. 

4.  Take care not to contaminate the detector probe tip. If the part is particularly dirty, it should be wiped off 

with a dry shop towel or blown off with shop air. No cleaners or solvents shall be used, since many 
electronic detectors are sensitive to their ingredients. 

5.  Visually trace the entire refrigerant system, and look for signs of air-conditioning lubricant leakage, 

damage, and corrosion on all lines, hoses, and components.  Each questionable area shall be carefully 
checked with the detector probe, as well as all fittings, hose to line couplings, refrigerant controls, service 
ports with caps in place, brazed or welded areas, and areas around attachment points and hold-downs on 
lines and components. 

6.  Always follow the refrigerant system around in a continuous path so that no areas of potential leaks are 

missed.  If a leak is found, always continue to test the remainder of the system. 

7.  At each area checked, the probe shall be moved around the location, at a rate no more than 25-50 mm/s 

and no more than 5 mm from the surface completely around the position. Slower and closer movement of 
the probe often helps locate the exact position of the leak. 

8.  An apparent leak shall be verified at least once by blowing shop air into the area of the suspected leak, if 

necessary, and repeating the check of the area. In cases of very large leaks, blowing out the area with 
shop air often helps locate the exact position of the leak. 

9.  Leak testing of the evaporator core while in the air conditioning module shall be accomplished by turning 

the air conditioning blower on high for a period of 15 sec. minimum, shutting it off, then waiting for the 
refrigerant to accumulate in the case for time specified by paragraph 10, then inserting the leak detector 
probe into the blower resistor block or condensate drain hold if no water is present, or into the closest 
opening in the heating/ventilation/air conditioning case to the evaporator, such as the heater duct or a vent 
duct.  If the detector alarms, a leak apparently has been found. 

10.  The accumulation time shall be 10 minutes.  

11.  Following any service to the refrigerant system of the vehicle, and any other service which disturbs the 

refrigerant system, a leak test of the repair and of the service ports of the refrigerant system shall be done.