A/C - R134A Leak Detection (Dye)
Classification:HA99-001a
Reference:
NTB99-011a
Date:
May 27, 1999
R-134A A/C SYSTEM REFRIGERANT DYE LEAK DETECTION
This amended version of NTB99-011 adds "claims information" regarding the use of a specific "Expense code" for reimbursement. Please discard all paper copies of NTB99-011.
APPLIED VEHICLES:
All with R-134a A/C system
SERVICE INFORMATION
A new leak detection tool is now available to assist in locating A/C refrigerant leaks. Using Kent-Moore kit # J-43926, fluorescent dye can be injected into the A/C system and if a leak exists the dye can be externally detected using a special ultraviolet lamp. This method of leak detection can save time as the entire A/C system can be quickly scanned to identify the location of leaks.
NOTE: This tool is not a replacement for the Nissan-approved electronic leak detector, and it should be used with an electronic leak detector to pin-point refrigerant leaks.
This bulletin provides an operating procedure for the Kent-Moore leak detection kit and outlines precautionary measures associated with its use.
IMPORTANT CAUTIONS:
Kit Usage Precautions
^ For your safety, read the manufacture's operating instructions and precautions provided with the tool prior to performing any work.
^ Use extreme care when handling fluorescent dye. If it is left on surfaces (such as exterior or interior paint/clear coat, painted plastic parts, painted bumper facias, interior plastic, etc.) for extended periods of time, it cannot be removed and a permanent stain will result. If a spill occurs, clean immediately with the supplied cleaning agent (# J-43872 or 3M(TM) dye cleaner P/N 051135-0899 can be used as an alternate) Do not spray these cleaning agents on hot surfaces (engine exhaust manifold, etc.).
^ Leak detection dyes for R-134a and R-12 A/C systems are different. Do not use R-134a leak detection dye in R-12 A/C systems or R-12 leak detection dye in R-134a A/C systems or A/C system damage may result.
^ Do not use more than one refrigerant dye bottle (1/4 ounce /7.4 cc) per A/C system.
^ Always wear UV goggles when operating the UV light; never stare into the UV light beam.
Additional Information
^ The A/C system may already contain a fluorescent leak detection dye for locating refrigerant leaks. (An ultraviolet (UV) lamp is required to illuminate the dye when inspecting for leaks.)
^ The fluorescent properties of the dye will remain for over three years unless a compressor seizure occurs, in which case new dye should be installed to guarantee fluorescence.
^ A compressor shaft seal that exhibits dye leakage should ONLY be repaired after the leak is confirmed using an approved electronic leak detector.
^ Always remove any dye from the leak area after repairs are complete to avoid mis-diagnosis during a future service.
^ The receiver dryer currently used in the Nissan R134a A/C systems has an operating life of approximately 10 years. It is not necessary to replace the receiver dryer in an R-134a system during routine service. Refer to NTB98-106 for more information.
Preliminary Checks
^ Perform a visual inspection of all refrigerant parts, fittings, hoses and components for signs of A/C lubricant leakage, damage and corrosion. A/C lubricant leakage may indicate an area of refrigerant leakage. Allow extra inspection time in these areas when using either an electronic refrigerant leak detector or fluorescent dye leak detector.
^ When searching for leaks, do not stop when one leak is found but continue to check for additional leaks at all system components and connections.
^ If dye is observed, confirm the leak with an approved electronic leak detector. It is possible a prior leak was repaired and not properly cleaned.
^ When searching for refrigerant leaks using an electronic leak detector, move the probe along the suspected leak area at 1 to 2 inches per second and no further than...inch from the component.
NOTE: Moving the electronic leak detector probe slower and closer to the suspected leak area will improve the chances of finding a leak.
SERVICE PROCEDURE
1. Verify the A/C system pressure (with the A/C system off) is 50 psi. Add refrigerant as needed to achieve 50 psi pressure.
2. Check the vehicle's A/C system to determine if refrigerant dye was previously installed.
NOTE: Vehicles equipped with refrigerant dye: (1) have an identification label (see Figure 1) installed near the Original Equipment (OE) A/C system charge label (2) have refrigerant dye residue inside the low side service fitting*
*It is normal for a small amount of refrigerant to be present in the low side service fitting. If refrigerant dye is present in the low side service fitting, this condition does not indicate a leak.
A. If the A/C system has refrigerant dye in it, proceed with step 4 (i.e., "With the engine off, check all components, fittings and lines for leaks").
B. If the A/C system does NOT have refrigerant dye, inject refrigerant dye as follows, then proceed with step 3 (i.e., "Operate the A/C system for 20 minutes").
1. Pour one bottle (1/4 ounce / 7.4 cc) of the A/C refrigerant dye into the injector tool (J-41459).
2. Connect the injector tool to the A/C LOW PRESSURE side service fitting.
3. Start the vehicle and turn on the A/C system (A/C compressor operating).
4. Inject the dye into the A/C system.
5. Disconnect the injector tool from the service fitting.
CAUTION: Do not allow dye to drip or spray when disconnecting the injector tool.
6. Install the refrigerant dye identification label next to the (OE) A/C system charge label (indicating the vehicle is now equipped with refrigerant leak detection dye).
7. Use a permanent marker to write the dye installation date on the dye identification label.
NOTE: If the A/C system refrigerant loop is "opened" due to a repair, the refrigerant dye can be poured directly into the open part of the A/C system.
3. Operate the A/C system for 20 minutes to allow the dye to mix with the refrigerant oil.
NOTE: Depending on the leak size, operating conditions and location of the leak, it may take from minutes to days for the dye to leak to a point that it is visible.
4. With the engine off, check all components, fittings and lines for leaks using the UV lamp and safety goggles in a shaded area.
NOTES:
^ The dye appears as a bright green/yellow fluorescent area at the point of leakage.
^ Fluorescence detected coming from the A/C evaporator drain tube typically indicates a leak in the evaporator core, tubes, fittings or TXV (Thermal Expansion Valve).
^ If it is difficult to shine the UV lamp directly on the suspected area, try using an adjustable mirror to reflect the light or wipe the area with a clean cloth and check for dye fluorescence on the cloth.
5. Repair confirmed refrigerant leaks.
6. Remove all residual dye using the recommended dye cleaner to prevent future mis-diagnosis.
7. Perform an A/C system performance test and confirm the leak repairs are successful using an approved electronic leak detector. Refer to the HA section of the applicable service manual for the A/C system performance procedure.
NOTE: Moving the electronic leak detector probe slower and closer to the suspected leak area will improve the chances of finding a leak.
PARTS INFORMATION
The Kent-Moore A/C system refrigerant dye leak detection kit (J-43926*) is an essential tool and will automatically be sent to all dealers.
NOTE: This kit does not contain the leak detection dye for R-12 A/C systems. To obtain the R-12 A/C system leak detection dye, order # J-39475 separately.
*Kit includes:
^ Ultra-violet lamp with shield/fluorescent enhancing safety goggles # J-42220
^ Refrigerant dye injector # J-41459
^ R-134a refrigerant dye # J-41447 (qty. 24)
^ Refrigerant dye cleaner # J-43872
NOTE: Refrigerant dye identification labels (qty. 30) are included with the refrigerant dye.
CLAIMS EXPENSE INFORMATION
To claim reimbursement for the single-use bottle of tracer dye as obtained from Kent Moore, use the Expense Code information.