A/C - New Leak Detector

Classification:
T&E98-001

Reference:
NTB98-063

Date:
July 15, 1998

NEW A/C LEAK DETECTOR

APPLIED VEHICLES:
All with air conditioning

SERVICE INFORMATION





A new A/C leak detector (Leybold Inficon D-TEK, tool number J41995) for R12 and R134a has been released as a dealer replacement for the Yokogawa J39400 leak detector (see Figure 1). While both units are approved by Nissan Motor Corporation for use, the operation, portability and response /recovery time of the D-TEK is improved over the Yokagawa unit. Use of the Yokogawa J39400 is still approved, however all replacements should be the D-TEK unit.

The simple calibration of the D-TEK combined with the following service procedure should reduce diagnostic time.

SERVICE PROCEDURE

1. Read all manufacture's operating and maintenance instructions before using the Inficon D-TEK for the first time.

2. Make sure the vehicle's A/C system has a minimum pressure of 50 psi.

3. Visually inspect the D-TEK's probe tip filter for contamination before use. Clean or replace the probe tip filter as needed.

4. Place the sensitivity selector in the HI position and move the power switch to the ON position. Check the unit for the following conditions:

^ The green lamp should be steady (not flashing) indicating the power cells are fully charged. If the green lamp is dim, out, or flashing, connect the power supply cord and charge the power cells.

NOTE:
The D-TEK can be operated while the power cells are re-charging, however this will lengthen the time required for a complete charge.

^ The alarm should sound and the seven yellow lamps will light for 15 to 20 seconds during warm-up. When the warm up is complete, the alarm and yellow lamps will go off. The D-TEK is now ready to be calibrated.

NOTE:
If the green lamp is not steady, or if there are any improper warm up conditions, refer to the operator's manual for trouble shooting procedures.





5. To calibrate the D-TEK, slowly pass the probe tip about... of an inch over the leak reference bottle, moving the probe about 1 - 2 inches per second to detect a leak rate of 0.5 ounces per year (see Figure 2). The alarm will sound and several yellow lamps will illuminate. Once the yellow lamps go out, the unit will have an audible click (about 2 clicks per second) which indicates the D-TEK is ready to use.

6. Visually inspect the entire A/C system for any signs of leakage or damage. If any are found, clean those areas thoroughly with a clean shop rag to prevent contamination to the D-TEK's probe.

7. Start the leak inspection at the compressor and move the probe (1 to 2 inches per second and no further than . .. inch from the components) in a continuous path along the high side line though the condenser core, receiver drier, evaporator, and back to the compressor on the low side line.

8. To inspect the evaporator core, first place the blower fan on high with the A/C compressor off for 15 seconds. Then turn the fan off and allow the system to set for 13 minutes. Inspect the evaporator drain hose and passenger side foot duct.

CAUTION:
Do not allow the probe tip to contact water.

NOTE:
When a leak is detected, the D-TEK will emit a different audible tone, and the yellow lamps will illuminate. It is important to move the probe past the suspected leak to get a proper reading as the D-TEK responds to changes in the concentration of refrigerant.

9. When the D-TEK signals a leak, pull the probe away for a moment, blow area with shop air, and then return it to the same location to isolate the leak. If the leak is large, move the sensitivity switch to LOW.

10. Return the sensitivity setting to HI and continue looking for other possible leaks until the entire A/C system is inspected.

NOTE:
When you reset the instrument to the HI sensitivity setting, as when you turned the unit ON initially, the yellow lights will illuminate and the tone will sound again momentarily.