For 1990-2009 cars

# INFORMATION ON J39400 A/C LEAK DETECTOR MAINTENANCE KIT

REVISION: 03/14/95

THIS BULLETIN IS BEING REISSUED TO REMIND DEALERS TO PERFORM MAINTENANCE ON THEIR A/C LEAK DETECTOR PRIOR TO THE START OF THE A/C SEASON. IT ALSO INCLUDES AN UPDATE ON ESSENTIAL TOOL STATUS AND AN INFORMATIONAL FLYER. PLEASE DISCARD BULLETIN 431218 (GROUP REFERENCE 1 - HVAC). ******************************************************************

#### SUBJECT: INFORMATION ON J39400 A/C LEAK DETECTOR MAINTENANCE KIT AVAILABILITY

#### MODELS: 1995 AND PRIOR VEHICLES WITH A/C

**IMPORTANT: TUNE UP YOUR LEAK DETECTOR BEFORE A/C SEASON BEGINS!**

BUICK, OLDSMOBILE AND GM OF CANADA MADE THE J39400-TUNEUP ESSENTIAL LAST SEASON.

CADILLAC MADE THE J39400-TUNEUP ESSENTIAL THIS SPRING. (CADILLAC FRANCHISES DUALED WITH BUICK AND/OR OLDSMOBILE WILL NOT RECEIVE ANOTHER J39400-TUNEUP).

REMEMBER: EVEN IF YOUR LEAK DETECTOR WAS TUNED UP LAST SEASON, IT MAY BE TIME FOR ANOTHER TUNE-UP!

#### CONDITION:

INADEQUATE MAINTENANCE REDUCES THE PERFORMANCE OF THE J39400 A/C LEAK DETECTOR.

#### CORRECTION:

A NEW MAINTENANCE KIT, P/N J39400-TUNEUP IS AVAILABLE FROM KENT-MOORE TOOL, WHICH CONTAINS THE FOLLOWING:

1. REPLACEMENT FILTERS (12) (P/N E7076EX INCLUDES AIR FLOW BALLS) 2. REPLACEMENT AIR FLOW BALLS (4) 3. REPLACEMENT CALIBRATED REFERENCE BOTTLE (P/N K9344AH) 4. REPLACEMENT SENSOR (P/N H10N04) 5. COTTON SWAB CLEANING STICKS (10) 6. SAFETY PIN 7. TUNE-UP/MAINTENANCE DATE LABEL REMINDER 8. INSTRUCTIONS

TO GUARANTEE UNINTERRUPTED SERVICE DURING PEAK COOLING SEASON,**ORDER THE J39400 TUNE-UP KIT ANNUALLY**, JUST BEFORE YOUR BUSY SEASON. ADDITIONAL TUNE-UP KITS OR INDIVIDUAL COMPONENTS CAN BE ORDERED AS NEEDED.

THE J39400 LEAK DETECTOR WAS SHIPPED TO DEALERS IN THE SPRING OF 1992 AS AN ESSENTIAL TOOL FOR USE ON R12 AND R134-A VEHICLES. CURRENTLY, THE J39400 IS THE ONLY LEAK DETECTOR WHICH MEETS GM REQUIREMENTS. MANY DETECTORS CAPABLE OF DETECTING R12 LEAKS ARE NOT SENSITIVE ENOUGH TO LEAK CHECK R134A A/C SYSTEMS. EVEN NEW LEAK DETECTORS DESIGNED FOR R134A VEHICLES MAY NOT MEET GM'S SENSITIVITY SPECIFICATIONS.

YOU CAN EXTEND THE LIFE OF THE SENSOR AND REDUCE MAINTENANCE COSTS IF YOU CALIBRATE THE J39400 PROPERLY AND MAINTAIN IT PROPERLY. THE J39400 IS A RUGGED INSTRUMENT, BUT IT IS NOT INDESTRUCTIBLE.

BE AWARE OF THE FOLLOWING BASIC INFORMATION COVERING THE SENSOR, FILTERS, AND CALIBRATION BOTTLE INCLUDED WITH THE J39400:

FILTER

THE FILTER IN THE TIP OF THE J39400 PROTECTS THE PUMP AND SENSOR FROM DUST AND MOISTURE. WITH THE HIGH SENSITIVITY OF THE J39400, YOU NEED NEVER TOUCH ANY SURFACE WITH THE TIP TO LOCATE THE LEAK. REPLACE THE FILTER OFTEN, AND IMMEDIATELY IF IT COMES IN CONTACT WITH MOISTURE OR IS VISIBLY DIRTY. USE THE FOLLOWING SCHEDULE.

OCCASIONAL USE: CHANGE WEEKLY REGULAR USE: CHANGE DAILY

KEEP PLENTY ON HAND. USE THE BLACK RUBBER PROBE TIP THAT CAME WITH THE DETECTOR TO KEEP THE FILTER AWAY FROM ACCIDENTAL CONTACT WITH THE SURFACE UNDER TEST.

CALIBRATED LEAK BOTTLE

THIS BOTTLE SIMULATES THE SMALLEST LEAK YOU NEED TO DETECT. YOU NEED TO CALIBRATE EACH TIME YOU USE THE LEAK DETECTOR.

**NOTE: NEVER OPEN THE LEAK BOTTLE. THE LEAK BOTTLE IS ACTIVATED WHEN YOU REMOVE AND DISCARD THE BLACK ADHESIVE DOT ON THE TOP OF THE CAP. IF YOU HAVE REMOVED THE INTERNAL WHITE SEAL, YOU HAVE DESTROYED THE ACCURACY OF THE LEAK AND YOU WILL NEED A REPLACEMENT.

NEVER EXPOSE THE J39400 TO THE LIQUID REFRIGERANT IN THE BOTTLE WITHOUT THE CAP IN PLACE.**

SENSOR

INCREASE THE LIFE OF YOUR SENSOR: USE THE LOWEST HEATER ADJUSTMENT SETTING AT WHICH THE J39400 DETECTS THE CALIBRATION LEAK. INCREASE HEATER ADJUSTMENT SETTING ONLY WHEN THE J39400 DOES NOT RESPOND TO THE CALIBRATION LEAK BOTTLE. NEVER CALIBRATE WITH ANYTHING OTHER THAN THE CALIBRATED LEAK BOTTLE. **NEVER INTENTIONALLY EXPOSE THE DETECTOR TO A BLAST OF REFRIGERANT, SUCH AS FROM AN OPEN SCHRADER VALVE.**

ADVICE FOR TROUBLE FREE OPERATION - SOME DO'S AND DON'TS:

. DON'T PRESS THE PROBE UP AGAINST A SURFACE UNDER TEST. . DON'T INTENTIONALLY PULL LIQUIDS INTO THE PROBE. . DON'T BLOCK THE AIR FLOW IN THE PROBE, THE SENSOR MOMENTARILY OVERHEATS AND WILL FALSE ALARM. . DON'T POKE FOAM INSULATION WITH THE PROBE. THE FOAM CONTAINS REFRIGERANT GAS AND THE J39400 WILL DETECT THIS AS A LEAK. . DO KEEP PLENTY OF SPARE FILTERS ON HAND. . DO CHANGE THE FILTER OFTEN, DAILY IF NECESSARY. . DO TRUST THE RESULTS OF THE J39400. IT CAN ONLY DETECT HALOGEN GAS AND WILL NOT ALARM ON ANY OTHER GAS. . DO USE ALL THREE SETTINGS ON THE J39400. THINK OF THE LABELS "GROSS", "R-12" AND "R134A" AS THREE SEPARATE SENSITIVITY SETTINGS FOR"LARGE", "MEDIUM", AND "SMALL". YOU CAN DETECT R-12 OR R134A ON ANY OF THESE SETTINGS.

DETECTING GROSS LEAKS WITH THE J39400:

ALWAYS USE COMPRESSED AIR LIBERALLY TO BLOW OUT RESIDUAL GAS BEFORE ATTEMPTING TO PINPOINT GROSS LEAKS. PLACE THE LEAK SIZE SWITCH IN THE "GROSS" POSITION. THE LEAK DETECTOR WILL RESPOND TO BOTH R12 AND R134A LEAKS IN THIS POSITION. YOU MAY HAVE TO WORK IN STAGES, GETTING CLOSER TO THE LEAK GRADUALLY BECAUSE THE ESCAPING GAS WILL FILL THE AREA UNDER TEST QUICKLY. CLEAR OUT TRAPPED GAS IN THE AREA TO BE TESTED WITH SHOP AIR. USE THE BALANCE CONTROL ON THE J39400 TO OBTAIN A SLOW CLICK RATE WHILE THE PROBE IS IN THE CONTAMINATED AREA. THE J39400 HAS ENOUGH RESOLUTION TO LOCATE THE HIGHER GAS LEVEL AT THE SOURCE OF THE LEAK, AS LONG AS YOU CAN BLOW OUT THE AREA FIRST.

AFTER YOU LOCATE AND REPAIR THE GROSS LEAK, MAKE SURE TO TEST THE COMPLETE SYSTEM AGAIN. YOU WILL PROBABLY PICK UP OTHER SMALLER LEAKS YOU COULD NOT FIND IN THE HIGH BACKGROUND CAUSED BY THE GROSS LEAK.

REMEMBER, IF YOU PERFORM SIMPLE MAINTENANCE TASKS ON THE J39400, YOU CAN:

. EXTEND THE LIFE OF THE SENSOR . ENSURE THE QUICK LOCATION OF LEAKS . VERIFY A SYSTEM TO BE LEAK FREE . FIND LEAKS FASTER . AND, YOU WILL REDUCE COMEBACKS.

SEE ATTACHED FLYER FOR MORE INFORMATION.

FIGURES: 0 ATTACHMENTS: 1

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.

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