Heating, Ventilation and Air Conditioning: Other GMC Sierra 2500

Fluorescent Leak Detector

1. Fluorescent dye will assist in locating any leaks in the A/C system.
2. The J 41447 dye mixes and flows with the PAG oil throughout the refrigerant system. Important: PAG oil is water soluble.
3. Condensation on the evaporator core or the refrigerant lines may wash the PAG oil and fluorescent dye away from the actual leak. Condensation may also carry dye through the HVAC module drain.
4. To prevent false diagnosis in the future, thoroughly clean the residual dye from any area where leaks were found. Use a rag and the approved fluorescent dye cleaner J 43872 .

Fluorescent Dye Injection

Important: J 41447 is the only A/C leak detection dye approved by General Motors.

1. Not all of the R-134a dyes are compatible with PAG oil. Some dyes decrease the oil viscosity or may chemically react with the oil.
2. R-134a leak detection dye requires time to work. Depending upon the leak rate, a leak may not become visible for between 15 minutes and 7 days. Important: Do NOT overcharge the A/C system with dye. This may cause reliability problems. Use only one 7.39 ml (0.25 oz) charge bottle of J 41447 .
3. With the A/C system charged, add J 41447 to the A/C system using J 41459 . Follow the instructions provided with J 41459 .
4. To prevent any false diagnosis, thoroughly clean any residual dye from the service port with a rag and the approved fluorescent dye cleaner J 43872 .
5. The dye injection package contains a notice sticker. Complete the leak detection information and place the sticker near the charge label.

A/C Compressor Shaft Seal Leak Detection with Dye

Use J 43872 to clean all traces of fluorescent dye from the A/C compressor shaft seal and reinspect the compressor.

1. Run the A/C system 15-30 minutes depending on the type of leak in order to circulate the dye.
2. Use J 42220 to inspect the A/C compressor shaft seal.
3. To prevent a future false diagnosis, thoroughly clean any residual dye from the area of the leak with a rag and the approved fluorescent dye cleaner J 43872 .

Service Ports

The sealing cap is the primary seal for the service ports. The cap contains an O-ring gasket that provides a leak-free seal. Install the cap tightly for leak-free sealing. The following conditions will cause a refrigerant loss

1. A loose cap
2. A missing cap
3. An incorrect cap

Use J 42220 or J 39400-A in order to test the service ports and sealing caps for leaks.

To prevent a false diagnosis, thoroughly clean any residual dye from the service port or sealing cap with a rag and the approved fluorescent dye cleaner J 43872 .

Evaporator Core

Use J 42220 in order to inspect the HVAC drain port. Follow the Fluorescent Dye Injection procedure if the A/C system does not contain fluorescent dye.

If only J 39400-A is available complete the following steps

1. With the engine running, turn the A/C ON.
2. Select the maximum blower motor speed for at least 15 seconds.
3. Turn OFF the engine.
4. Turn OFF the blower motor.
5. Wait 10 minutes.
6. Turn ON the blower motor and select the lowest speed.
7. Insert the leak detector probe into one of the center instrument panel outlets. Try to get as close to the evaporator as possible.
8. A solid alarm on the detector indicates a leak.

Halogen Leak Detector

Ensure that the vehicle has at least 0.45 kg (1 lb) of refrigerant in the A/C refrigeration system in order to perform a leak test. Refer to Refrigerant Recovery & Recharging for recharging the A/C system.

Important: Halogen leak detectors are sensitive to the following items

1. Windshield washing solutions
2. Many solvents and cleaners
3. Some adhesives used in the vehicle

Clean and dry all surfaces in order to prevent a false warning. Liquids will damage the detector.

Important: Follow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.

The J 39400-A is a small unit that operates on 12 volts DC. The J 39400-A provides an audible signal that increase in frequency as the unit detects R-134a. Follow the instructions included with the unit in order to properly calibrate the instrument. Use the detector in the proper setting for the type of tested refrigerant.

The most common leaks occur at the refrigerant fittings or connections. The leaks may be the result of any of the following conditions

1. Improper torque
2. Damaged O-rings or sealing washers
3. Lack of lubricant on O-rings
4. Dirt or debris across the O-ring or sealing washers

Maintain a proper scan rate in order to successfully use the J 39400-A or any other electronic leak detector. Carefully follow the manufacturer's instructions regarding the following items

1. Calibration
2. Operation
3. Maintenance

In order to test for leaks, complete the following steps

1. Completely and slowly circle each joint with the probe.
2. Place the tip of the probe as close as possible to the surface, but no more than 6 mm (0.25 in) away. Do not block the probe tip air intake.
3. A leak exists when the audible tone goes from a steady 1-2 clicks per second to a continuous alarm.
4. Frequently adjust the balance knob in order to maintain the rate of 1-2 clicks per second.

Use J 39400-A to inspect each hose connection.

Scheme 91

Use J 39400-A to inspect all the electrical sensors and switches located in the A/C lines.

Use J 39400-A to inspect the service ports.

If you know that the system has lost the refrigerant charge and you cannot find a leak using J 39400-A , follow the Fluorescent Dye Injection procedure using J 42220 .

Scheme 92

A/C Compressor Shaft Seal Leak Detection with J-39400-A

1. Blow compressed air into the following locations for at least 15 seconds: Behind the A/C compressor clutch/pulley In front of the A/C compressor clutch/pulley
2. Wait 1-2 minutes.
3. Probe the area in front of the pulley.
4. Probe the area behind the pulley.
5. A solid alarm from the detector indicates a leak.

Eliminating Air Conditioning Odor

Odors may be emitted from the air conditioning system primarily at start up in hot, humid climates.

The following conditions may cause the odor

1. Debris is present in the HVAC module.
2. Microbial growth on the evaporator core

When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. To remove odors of this type, the microbial growth must be eliminated. Perform the following procedure

Deodorize the evaporator core using Deodorizing Aerosol Kit.

Perform the following steps in order to deodorize the A/C system

1. Ensure that the plenum which draws outside air into the HVAC module is clear of debris.
2. Disable the A/C compressor clutch operation by disconnecting the clutch coil electrical connector.
3. Dry the evaporator core by performing the following steps: 3.1. Start the engine. 3.2. Select the warmest temperature setting. 3.3. Select the recirculation mode. 3.4. Run the blower motor on high for 10 minutes.
4. Locate an area in the air conditioning duct between the blower motor and the evaporator core downstream of the blower motor.
5. Drill a 3.175 mm (0.125 in) hole where the hole will not interfere with or damage the following components: The blower motor The evaporator core Any other operating part the of system
6. Wear safety goggles and latex gloves in order to perform the following actions: 6.1. Select the maximum blower speed. 6.2. Insert the deodorizer extension tube into the hole to the mark on the extension tube. 6.3. Use short spray bursts and vary the direction of spray for a 2-3 minute period of time.
7. Shut the engine OFF. Allow the vehicle to sit for 3-5 minutes.
8. Seal the 3.175 mm (0.125 in) hole with body sealer or RTV gasket compound.
9. Start the engine.
10. Operate the blower motor on high for 15-20 minutes to dry.
11. Reconnect the A/C compressor clutch coil electrical connector.
12. Verify proper clutch operation.

Refrigerant Recovery & Recharging

Note. R-134a is the only approved refrigerant for use in this vehicle. The use of any other refrigerant may result in poor system performance or component failure.

Note. To avoid system damage use only R-134a dedicated tools when servicing the A/C system.

Note. Use only Polyalkylene Glycol Synthetic Refrigerant Oil (PAG) for internal circulation through the R-134a A/C system and only 525 viscosity mineral oil on fitting threads and O-rings. If lubricants other than those specified are used, compressor failure and/or fitting seizure may result.

Note. R-12 refrigerant and R-134a refrigerant must never be mixed, even in the smallest of amounts, as they are incompatible with each other. If the refrigerants are mixed, compressor failure is likely to occur. Refer to the manufacturer instructions included with the service equipment before servicing.

Tools Required

1. J 43600 ACR 2000 Air Conditioning Service Center
2. J 45037 A/C Oil Injector

The J 43600 is a complete air conditioning service center for R-134a. The ACR 2000 recovers, recycles, evacuates and recharges A/C refrigerant quickly, accurately and automatically. The unit has a display screen that contains the function controls and displays prompts that will lead the technician through the recover, recycle, evacuate and recharge operations. R-134a is recovered into and charged out of an internal storage vessel. The ACR 2000 automatically replenishes this vessel from an external source tank in order to maintain a constant 5.45-6.82 kg (12-15 lbs) of A/C refrigerant.

The ACR 2000 has a built in A/C refrigerant identifier that will test for contamination, prior to recovery and will notify the technician if there are foreign gases present in the A/C system. If foreign gases are present, the ACR 2000 will not recover the refrigerant from the A/C system.

The ACR 2000 also features automatic air purge, single pass recycling and an automatic oil drain.

Refer to the J 43600 ACR 2000 manual for operation and setup instruction. Always recharge the A/C System with the proper amount of R-134a. Refer to Refrigerant System Capacities for the correct amount.

A/C Refrigerant System Oil Charge Replenishing

If oil was removed from the A/C system during the recovery process or due to component replacement, the oil must be replenished. Oil can be injected into a charged system using J 45037 . For the proper quantities of oil to add to the A/C refrigerant system, refer to Refrigerant System Capacities .

Clutch Rotor And/Or Bearing Install (HT6/HD6/HU6)

Tools Required

1. J 6083 External Snap Ring Pliers
2. J 33023-A Puller Pilot
3. J 41552 Compressor Pulley Puller
4. J 29886 Driver Handle
5. J 21352-A Support Block
6. J 9481-A Bearing Installer
7. J 33019 Bearing Staking Tool
8. J 33017 Pulley and Bearing Assembly Installer
9. J 8433-1 Puller Bar
10. J 8433-3 Forcing Screw
11. J 34992 Compressor Holding Fixture

Note. Do not support the rotor by resting the pulley rim on a flat surface during the bearing installation or the rotor face will be bent.

Scheme 93

Scheme 94

Scheme 95

Scheme 96

1. Place the pulley rotor on the J 21352-A in order to fully support the rotor hub during bearing installation.
2. Use the following tools in order to align the new bearing squarely with the hub bore: The J 41552 The J 9481-A The J 29886
3. Drive the bearing fully into the hub. The installer will apply force to the outer race of the bearing, if used as shown.
4. Place the J 33019 in the hub bore.
5. Shift the rotor and bearing assembly on the J 21352-A in order to fully support the hub under the staking pin location. Use a heavy-duty rubber band (1) in order to hold the stake pin in the guide. Properly position the stake pin in the guide after each impact on the pin. CAUTION: Use care in order to prevent personal injury when striking the staking pin with a hammer.
6. Strike the staking pin with a hammer until a metal stake, similar to the original, forms down to, but not touching, the bearing. Important: Noisy bearing operation and reduced bearing life may result if the outer bearing race is deformed while staking. Ensure that the stake metal does not contact the outer race of the bearing.
7. Stake 3 locations on the bearing race 120 degrees apart as shown.
8. With the compressor mounted on the J 34992, position the pulley rotor (1) and the bearing assembly on the front head.
9. Position the J 33017 and the J 33023-A directly over the inner race of the bearing.
10. Position the J 8433-1 on the J 33023-A.
11. Assemble the 2 through bolts and the washers through the puller bar slots.
12. Thread the through bolts into the J 34992 . Ensure that the thread of the through bolts engage the full thickness of the J 34992 .
13. Tighten the center screw in the J 8433-1 in order to force the pulley rotor and bearing assembly onto the compressor front head. If the J 33017 slips off direct in-line contact with the inner race of the bearing, perform the following steps: 13.1. Loosen the J 8433-3 . 13.2. Realign the installer and the pilot in order to ensure that the J 33017 properly clears the front head.
14. Use the J 6083 in order to install the following components: The pulley rotor (1) The retaining ring (2)
15. Install the clutch plate and hub assembly. Refer to «Compressor Clutch Plate/Hub Assembly Replacement (HD6/HT6/HU6)»(ref-175819-S24080760842005042700000) .

Scheme 97

1. Install the coil assembly to the compressor.
2. Install the coil snap ring.
3. Install the coil connector retaining bracket screw. Tighten the screw to 9 N.m (80 lb in).
4. Install the clutch hub/bearing assembly.
5. Install the clutch hub/bearing snap ring.
6. Install the clutch plate assembly.
7. Install the clutch plate retaining bolt (1). Tighten the bolt to 18 N.m (13 lb ft).

Compressor Clutch Coil Install (HT6/HD6/HU6)

Tools Required

1. J 33024 Clutch Coil Installer Adapter
2. J 8433-1 Puller Bar
3. J 8433-3 Forcing Screw
4. J 34992 Compressor Holding Fixture
5. J 33017 Pulley and Bearing Assembly Installer
6. J 33023-A Puller Pilot
7. J 6083 External Snap Ring Pliers

Scheme 98

Scheme 99

Scheme 100

Scheme 101

1. Place the clutch coil assembly (1) on the front head. Position the terminals at the marked location.
2. Place the J 33024 over the internal opening of the clutch coil housing.
3. Align the J 33024 with the compressor front head.
4. Center the J 8433-1 in the counter-sunk center hole of the J 33024.
5. Install the 2 through bolts and washers through the crossbar slots.
6. Thread the bolts into the J 34992 in order to achieve full fixture thickness.
7. Turn the center forcing screw of the J 8433-1 in order to force the clutch coil onto the front head. Ensure that the clutch coil and the J 33024 remain aligned during installation.
8. When the coil is fully seated on the front head, use a 1/8 inch diameter drift punch (2) in order to stake the front head at 3 places 120 degrees apart (3), in order to ensure that the clutch coil (1) remains in position.
9. Ensure that the stake size is only one-half the area of the punch tip. Ensure that the stake is only approximately 0.28-0.35 mm (0.010-0.015 in) deep.
10. With the compressor mounted to the J 34992, position the pulley rotor (1) and bearing assembly on the front head.
11. Position the J 33017 and the J 33023-A directly over the inner race of the bearing.
12. Position the J 8433-1 on the J 33023-A.
13. Assemble the 2 through bolts and washers through the puller bar slots.
14. Thread the bolts into the J 34992. Ensure that the thread of the through bolts engages the full thickness of the J 34992.
15. Tighten the center screw in the J 8433-1 in order to force the pulley rotor and bearing assembly onto the compressor front head. If the J 33017 slips off direct in-line contact with the inner race and bearing, perform the following steps: 15.1. Loosen the J 8433-3. 15.2. Realign the installer and the pilot in order to ensure that the J 33017 properly clears the front head.
16. Use the J 6083 in order to install the following components: The pulley rotor (1) The retainer ring (2)
17. Install the clutch plate and hub assembly. Refer to «Compressor Clutch Plate/Hub Assembly Replacement (HD6/HT6/HU6)»(ref-175819-S24080760842005042700000) .

Compressor Pressure Relief Valve Install (HT6/HD6/HU6)

Tools Required

1. J 43600 ACR 2000 Air Conditioning Service Center
2. J 39400-A Halogen Leak Detector

1. Clean the valve seat area on the rear head.
2. Lubricate the O-ring of the new pressure relief valve (5) and the O-ring assembly using new 525 viscosity refrigerant oil.
3. Install the new pressure relief valve (5). Tighten the new valve to 9.0 N.m (80 lb in).
4. Evacuate and recharge the system using the J 43600 .
5. Leak test the fitting(s) of the repaired or reinstalled component using the J 39400-A .

Compressor Control Switches Install (HT6/HD6/HU6)

Tools Required : J 5403 Snap Ring Pliers

Important: If you reinstall an existing control switch in the compressor, use a new O-ring and a new retainer ring. An O-ring and a retainer ring are included in a new switch kit.

1. Lubricate the new O-ring using clean refrigerant oil.
2. Install the new O-ring into the groove in the switch cavity.
3. Lubricate the control switch housing using clean refrigerant oil.
4. Install the switch (2) into the switch cavity until the switch bottoms in the cavity.
5. Using the J 5403, install the switch retaining ring. Ensure that the high point of the curved sides is adjacent to the switch housing. Ensure that the retaining ring is properly seated in the switch cavity retaining groove.
6. Leak test according to bench test procedure.