A/c Compressor Overhaul - da-6 Chevrolet Camaro II

DESCRIPTION

The compact, all-metric General Motors (Delco Air) DA-6 6-cylinder compressor weighs less than 12 1/2 pounds and is only 9 1/4 inches long. Its combination drive shaft and axial plate drives 3 double-acting pistons back and forth in their 6 cylinders - 3 at each end. (Scheme 64)

The cylinder assembly and both compressor heads are made of die-cast aluminum. The compressor has no oil slump, but holds additional oil when the cycling clutch disengages.

The discharge (high pressure) side is in the compressor center cavity, and the suction (low pressure) side is in the outside cavity. Discharge crossover is a drilled hole in both front and rear heads.

All vehicles, equipped with the DA-6, use the same compressor. Variations, however, occur in mounting bracket (front head) position on cylinder assembly, and in drive systems, pulleys, connections, and system capacities.

Exploded View of General Motors DA-6 6-Cylinder Compressor (Components of center cylinder and piston assembly are non-serviceable, and must be replaced as an assembly.). Scheme 64

OVERHAUL INFORMATION

Note. The DA-6 compressor can be overhauled in the field, if proper fixtures, tools and gauges are used. Center cylinder and piston assembly is non-serviceable, and must be replaced as a single unit. Shaft seal and drive components (clutch, pulley, clutch coil) can be overhauled without disturbing the compressor's internal parts. Instructions for such service are at the end of this article.

Most major overhaul procedures require that the system be discharged and that the compressor be removed from the vehicle for bench repair. Special metric tools are required for the compressor.

Take every precaution to keep dirt or other contaminants out of compressor. Be sure work bench area is clean.

When overhauling compressor, drain oil, measure the amount removed, and discard it. Oil leaking from compressor during reassembly, should also be caught, measured, and discarded. When repairs are completed, new refrigerant oil should be added equal to measured amount.

Removal

Discharge system using approved refrigerant recovery/recycling equipment, and remove pressure relief valve from center of rear head.

Installation

1. Using new refrigerant oil, lubricate "O" ring of new pressure relief valve assembly. Install new valve, and torque to 5.5-7.7 ft. lbs.
2. Evacuate, recharge and leak test system.

1. Discharge system using approved refrigerant recovery/recycling equipment. Disconnect electrical connector from high pressure cut-off switch in compressor rear head. Remove switch retaining ring, using J-5403 internal snap ring pliers.
2. Remove switch from compressor by pulling on terminal housing. Using J-9553 or J-9553-01 "O" ring removal tool, remove old O" ring seal from switch cavity.

1. Check switch cavity and "O" ring groove in rear head for dirt or other foreign material. Clean as necessary. Dip new "O"ring in clean refrigerant oil, and install it in groove in switch cavity. NOTE: If same switch is to be reinstalled, a new "O" ring must be used, and preferably a new retaining ring. If a new switch is being installed, parts come in the kit.
2. Lubricate switch housing with clean refrigerant oil, and carefully insert switch into cavity until it bottoms. Using J-5403 internal snap ring pliers, install switch retaining ring with high point of curved sides next to switch housing.
3. Be sure ring is properly seated in cavity retaining ring groove. Leak test around switch.

Scheme 65

Scheme 66

Scheme 67

1. Discharge system using approved refrigerant recovery/recycling equipment and remove compressor from vehicle. Drain, measure, and discard compressor's refrigerant oil. Remove clutch hub and drive plate, pulley and bearing assembly, and clutch coil, according to procedures at end of this article.
2. Mark location, and note alignment of rear head, center cylinder assembly, and front head. (Scheme 65) Front head is assembled differently for mounting on different model applications. (Scheme 66) Remove 6 compressor through bolts and discard their gaskets. CAUTION: Front head must ALWAYS be assembled on cylinder assembly so suction inlet port on rear head will be at top (12 o'clock position) when compressor is installed on vehicle. Otherwise compressor will not receive proper lubrication. Center cylinder assembly has 3 locating marks: "I" for standard front head location, "II" for 120° counterclockwise head location, and "III" for 120° clockwise head location. (Scheme 66) The PROPER cylinder marking for specific vehicle must be aligned with head alignment marks or damage will occur. (Scheme 65): Marking Compressor for Reassembly (Scribe both heads and center cylinder assembly.) (Scheme 66): 3 Mounting Angles Are Used Depending on Vehicle Application (Rear head suction port must always be in 12 o'clock position when compressor is installed.)
3. Using a wood or plastic block and plastic-headed hammer, tap around edge of rear head to disengage it from cylinder assembly. (Scheme 67) Separate rear head, head gasket, rear valve plate, suction reed plate, and cylinder-to-rear head "O" ring. Discard head gasket and "O" ring. (Scheme 67): Removing Rear Head from Compressor (Front head is removed in a similar manner.)
4. Inspect rear valve plate, suction reed plate, and visible portion of cylinder assembly. Replace components as necessary.

Scheme 68

Scheme 69

1. Attach front head and cylinder assembly to J-33026 compressor holding fixture. Using masking tape or equivalent, tape across through bolt holes that are just clockwise from 6 o'clock and 12 o'clock positions. (Scheme 68) Install J-33016 assembly guide pins so they rest on tape, with small ends upward. (Scheme 68): Installing Assembly Guide Pins (Make sure pins are in correct bolt holes.)
2. Lubricate a new cylinder-to-rear head "O" ring with clean refrigerant oil. Install "O" ring in rear cylinder "O" ring groove. NOTE: "O" ring may be positioned on rear cylinder, and rolled into "O" ring groove. Be sure cylinder surface is first cleaned with solvent and blown dry.
3. Install suction reed plate over guide pins, followed by rear valve plate, and head gasket. (Scheme 69) (Scheme 69): Installing Rear Suction Reed Plate, Rear Valve Plate, & Head Gasket (Be sure to position components over guide pins exactly as shown.)
4. Carefully assemble rear head over guide pins, making sure guide pins extend into proper threaded holes in rear head. When properly inserted, head will not rotate. It will be aligned with and will lower into position on rear cylinder. Alignment marks made previously should align.
5. Using both hands, press downward on rear head to force it over "O" ring above rear cylinder.
6. Add new gaskets to 6 through bolts. Install 4 bolts into compressor assembly. Be sure these 4 bolts are properly threaded into rear head before removing tape and 2 guide pins. Install last 2 through bolts, and alternately tighten all 6 bolts to 72-84 INCH lbs.
7. Install J-9625-A leak test plate on rear head of compressor, and leak test complete compressor assembly. Remove test plate, and add same amount of new refrigerant oil as was originally drained and measured.

1. Discharge system using approved refrigerant recovery/recycling equipment and remove compressor from vehicle. Drain, measure, and discard compressor's refrigerant oil. Remove clutch hub and drive plate, pulley and bearing assembly, clutch coil, and shaft seal. according to procedures at end of this article.
2. Mark location, and note alignment of rear head, cylinder assembly, and front head. (Scheme 65) Front head is aligned differently for different model applications. Remove 6 compressor through bolts, and discard their gaskets. NOTE: Front head must ALWAYS be assembled on cylinder assembly so suction inlet port on rear head will be at top (12 o'clock position) when compressor is installed on vehicle. Otherwise compressor will not receive proper lubrication. Center cylinder assembly has 3 locating marks: "I" for standard head location, "II" for 120° counterclockwise head location, and "III" for 120° clockwise head location. (Scheme 66) The PROPER cylinder marking for specific vehicle must be aligned with head alignment marks or damage will occur.
3. Using a wood or plastic block and plastic-headed hammer, tap around edge of front head to disengage it from cylinder assembly. (Scheme 67) Separate front head, head gasket, front valve plate, suction reed plate, and cylinder-to-front head "O" ring. Discard head gasket and "O" ring.
4. Inspect front valve plate, suction reed plate, and visible portion of cylinder assembly. Replace components as necessary.

Scheme 70

Scheme 71

1. Rest rear head and cylinder assembly on J-21352 support block so pressure relief valve and switches are in block's holes. Install J-33016 assembly guide pins in proper through bolt holes. (Scheme 70) Lubricate a new front head-to-cylinder "O" ring, using clean refrigerant oil. Install in front cylinder "O" ring groove. (Scheme 70): Rear Head and Cylinder Assembly (Note guide pin location in relationship to front discharge crossover cavity.)
2. Install suction reed plate, front valve plate, and head gasket in order over guide pins. (Scheme 71) (Scheme 71): Installing Front Suction Reed Valve, Front Valve Plate, & Head Gasket (Be sure components are installed exactly as shown.)
3. Line up mark on front head with alignment marks scribed on compressor cylinder assembly and rear head during removal. Assemble head over guide pins.
4. Using both hands, press down on front head to force it over "O" ring at front cylinder.
5. Add new gaskets to all 6 through bolts, and install them into compressor assembly. Be sure 4 of the bolts thread into rear head, before removing assembly guide pins. Alternately tighten to 72-84 INCH lbs.
6. Install new shaft seal kit. Add new refrigerant oil in an amount equal to that previously drained and measured. Install J-9625-A test plate. Place shaft nut on shaft, and rotate shaft several turns.
7. Leak test complete compressor assembly. Remove shaft nut, and install clutch coil, pulley and bearing assembly, clutch hub and drive plate, and shaft nut. Install compressor on vehicle. Evacuate and charge system.

Perform steps 1 through 3 of Compressor Front Head Assembly Removal and step 3 of Compressor Rear Head Assembly Removal. Three component groups will result - front head assembly, cylinder and shaft assembly, and rear head assembly.

Scheme 72

Scheme 73

1. Place rear compressor head on J-21352-A support block, and install 2 J-33016 guide pins into mounting holes. In order, install head gasket, rear valve plate, and suction reed plate on rear head. (Scheme 72) (Scheme 72): Assembling Rear Components on Rear Head (Assemble parts in correct relationship to guide pins.)
2. Install cylinder-to-rear head "O" ring and cylinder and shaft assembly. (Scheme 73) Using both hands, press cylinder and shaft assembly down into rear head. Lubricate and install cylinder-to- front head "O" ring. (Scheme 73): Front View of Cylinder Assembly (Front of cylinder will be up during assembly.)
3. Complete installation by following steps 2 through 7 of Compressor Front Head Assembly Installation.

Scheme 74

1. Should a leak occur between front and rear cylinder halves, remove cylinder and shaft assembly from heads as previously outlined.
2. Using a wood block and plastic-headed hammer, tap around rear cylinder to separate the 2 halves approximately 1/2 - 5/8". (Scheme 74) Remove center "O" ring. CAUTION: Use care when separating cylinder halves so pistons are not pulled from their cylinder bores. If one is accidentally removed, carefully align piston and slide it back into its bore. (Scheme 74): Replacing Center Cylinder "O" Ring (Separate cylinder assemblies only 1/2 - 5/8".)
3. Check to be sure the small "O" ring at the discharge crossover is still in place. It should be in recess in rear half, but may stick to front half of cylinder assembly at separation. "O" ring may be reused. If lost, however, a new one must be installed.
4. Fasten front head in J-33026 holding fixture. Insert cylinder and shaft assembly into front head, with shaft downward. Be sure proper scribe mark is aligned with head alignment marks, depending upon model application.
5. Using clean refrigerant oil, lubricate the new center "O" ring, its groove in front cylinder, and its sealing surface on rear cylinder. Install center "O" ring in its groove.
6. With discharge crossover "O" ring still in place, insert a piece of 5/16" drill rod through discharge crossover passage in both cylinder halves to properly align cylinder. Using both hands, carefully press cylinder halves together. Remove drill rod. Complete installation of other components, as outlined previously.

LEAK TESTING COMPRESSOR

1. Install J-9625-A leak testing plate on rear head of compressor. Attach center hose of manifold gauge of charging station to refrigerant drum in the upright position.
2. Using either J-5420 gauge adapters or hoses equipped with valve depressors, connect high and low pressure charging station hoses to corresponding fittings on J-9625-A test plate. NOTE: Low side compressor port has a larger internal opening than high side port.
3. Open low pressure valve, high pressure valve, and refrigerant valve on charging station, permitting R-12 vapor to flow into compressor.
4. Using a leak detector, check for leaks at pressure relief valve, rear head switch location, compressor front and rear head "O" rings, center cylinder "O" ring, through bolt gaskets, and shaft seal.
5. Shut charging station valves to prevent refrigerant flow. If leaks exist, correct and recheck. Loosen hose connections at J-5420 adapters or manifold gauge to release vapor pressure from compressor. Disconnect both gauge adapters or hoses from test plate.
6. Add 3 ounces of new 525 viscosity refrigerant oil. Without turning compressor shaft or clutch hub, slowly rotate the complete compressor several times. This will permit oil to lubricate all of the six cylinders. If clutch hub and drive plate assembly is not installed, install shaft nut temporarily.
7. Using clutch hub or a wrench on shaft nut, rotate compressor shaft several turns to lubricate pistons and cylinder bores. Reconnect charging station high pressure hose or a high pressure gauge and J-5420 gauge adapter to J-9625-A test plate high side connector.
8. Attach a J-5420 adapter or depressor-type hose to low pressure port of J-9625-A test plate to open the Schrader valve. NOTE: Oil will drain from compressor low side port adapter if compressor is positioned with low side port downward.
9. Attach compressor to a J-33026 holding fixture. Mount compressor in a vise so compressor is horizontal and shaft can be turned with a wrench. Rotate shaft 10 turns at a speed of 1 revolution per second. Check high side gauge reading after 10th revolution.
10. A good pumping compressor should have a gauge reading of 100 psi or more. A pressure of less than 90 psi would indicate leaking of suction or discharge valves, an internal leak, or an inoperative valve. Compressor should be disassembled, checked, and repaired. Repeat pumping test, and leak test compressor externally.
11. When pressure pumping test is complete, release air pressure from high side and remove gauge adapters and test plate. Tilt compressor so compressor high and low side ports are down. Let oil drain from compressor for 10 minutes.
12. Install proper amount of new refrigerant oil through low side port. Install compressor in vehicle, and evacuate and charge the system.

DA6 COMPRESSOR SERVICE TOOLS PART NUMBERS

GENERAL MOTORS DA6 6-CYLINDER COMPRESSOR SERVICE TOOLS

Mounting Compressor - Tool Reference No. 1 Holding Fixture. Scheme 75

Discharge refrigerant using approved refrigerant recovery/recycling equipment, and remove compressor. Mount compressor in holding fixture, secured in a vise.

Remove Shaft Nut - Tool No. 2-Clutch Holder Wrench, No. 3-Shaft Nut Socket. Scheme 76

While holding clutch assembly with clutch holder wrench, remove shaft nut using shaft nut socket.

Remove Clutch Assembly - Tool Reference No. 4-Hut & Drive Plate Remover/Installer. Scheme 77

With center screw tip against end of shaft, thread hub and drive plate remover into hub. Hold body of remover with a wrench and turn center screw.

Removing Key. Scheme 78

Using side cutters, remove shaft key and save it for later reassembly.

Removing Snap Ring - Tool No. 5-Internal Snap Ring Pliers. Scheme 79

Using internal snap ring pliers, remove snap ring retaining seal seat.

Clean Shaft Area. Scheme 80

Thoroughly clean compressor neck area around shaft to prevent entrance of dirt or other foreign material.

Install seal protector - Tool No. 7-Shaft Seal Protector. Scheme 81

Place shaft seal protector over end of shaft to avoid chipping ceramic seal seat.

Removing Seal Seat - Tool No. 9-Seal Remover/Installer. Scheme 82

Fully engage tangs of seal seat remover into recessed portion of seal seat by turning handle clockwise. Remove seal seat with a twisting, pulling motion. Discard seal seat.

Removing Seal - Tool No. 9-Seal Remover/Installer. Scheme 83

Slide seal remover over seal protector, pressing down while turning tool clockwise. Engage remover tangs with tabs on seal assembly. Lift seal assembly out, and discard it.

Removing "O" Ring - Tool No. 10-Seal "O" Ring Remover. Scheme 84

Using an "O" ring remover, remove and discard "O" ring from compressor neck. Clean compressor neck area thoroughly before installing new parts.

Installing "O" Ring - Tool No. 11-Seal "O" Ring Installer. Scheme 85

Dip new seal seat "O" ring in clean refrigerant oil and place on"O" ring installer. Insert installer into compressor neck until it bottoms. Lower installer's moveable slide to release "O" ring into lower groove. Rotate installer to seat "O" ring. Remove installer.

Lubricating Seal - Tool No. 9-Seal Remover/Installer. Scheme 86

Dip face of seal assembly into clean refrigerant oil. Install seal assembly on seal installer by engaging tabs of seal with tangs of installer.

Installing Seal - Tool No. 7-Shaft Seal Protector, No. 9-Seal Remover/Installer. Scheme 87

Place seal protector over end of shaft. With a twisting motion, push new seal assembly and installer downward over seal protector. Be sure seal engages flats on shaft and is fully seated. Press downward on installer and twist counterclockwise to release seal assembly. Remove installer.

Installing Ceramic Seat - Tool No. 8-Seal Seat Remover/ Installer. Scheme 88

Attach ceramic seal seat to seal seat installer. Dip seat in clean refrigerant oil. Install seat over seal protector, pushing seat into place with a rotary motion. Remove installer and seal a protector.

Installing Snap Ring - Tool No. 5-Internal Snap Ring Pliers. Scheme 89

Using internal snap ring pliers,install snap ring in compressor neck. Use sleeve from seal seat installer to press snap ring into its groove.

Leak Testing Compressor - Tool No. 20-Leak Test Fixture. Scheme 90

Install compressor leak test fixture on rear head. Connect manifold gauge charging lines. Pressurize low and high sides to drum pressure. Temporarily install shaft nut. With compressor in horizontal position, turn compressor shaft by hand several turns in normal direction. Check for leaks and remove shaft nut.

Installing Clutch Assembly - Tool No. 4-Hub & Drive Plate Remover/ Installer. Scheme 91

1. Place clutch drive plate and hub assembly on shaft. Do not drive or pound on clutch hub or shaft, as internal compressor damage will result.
2. Remove tip from installer center screw and reverse body direction on center screw. Install drive plate installer with bearing. Back off installer body to allow center screw to be threaded fully onto end of shaft.
3. Hold center screw with wrench. Tighten hex portion of installer body to press hub onto shaft. Tighten body several turns. Remove installer. Be sure shaft key is still in place before installing clutch assembly to its final position.

Checking Air Gap. Scheme 92

Using feeler gauge, check air gap between clutch plate and pulley surfaces. Gap should be .015-.025.

Installing Shaft Nut - Tool No. 2-Clutch Holder Wrench, No. 3-Shaft Nut Socket. Scheme 93

Hold clutch assembly with clutch holding tool. Tighten shaft nut against shaft shoulder, using shaft nut socket. Tighten to 8-16 ft. lbs. Spin pulley by hand to be sure pulley and clutch drive plate are not rubbing. Install compressor, evacuate and charge.

Remove Snap Ring - Tool No. 6-External Snap Ring Pliers. Scheme 94

Perform steps 1-4 of "SEAL REPLACEMENT". Using external snap ring pliers, remove snap ring retaining pulley and bearing assembly.

Install Puller Pilot Tool (Reference No. 14-Puller Pilot, No. 12-Pulley Puller.). Scheme 95

Install puller pilot to front head. Install pulley puller down into inner circle of slots in pulley. Turn puller clockwise to engage puller tangs in segment of pulley between slots.

Remove Pulley & Bearing. Scheme 96

Hold puller in place and tighten puller screw against puller pilot. Remove pulley and bearing assembly from compressor head.

Remove Bearing - Tool No. 17-Support Block, No. 21-Bearing Remover, No. 18-Driver Handle. Scheme 97

Using support block, support the pulley hub properly. remove forcing screw from puller. Without removing puller from pulley, turn assembly over, and rest pulley on puller. Drive out bearing with bearing remover and a driver.

Note. It is not necessary to remove staking to remove bearing, but staking should be filed away before installing new bearing.

Install Bearing - Tool No. 22-Bearing Installer, No. 18-Driver Handle. Scheme 98

Place pulley on support block. Be sure to fully support pulley hub, not rim. Align new bearing squarely with pulley hub bore. Using bearing installer and driver handle, drive bearing fully into hub. Installer should apply force to bearing outer race.

Stake Bearing - Tool No. 17-Support Block, No. 19-Staking Tool. Scheme 99

Place bearing staking guide and pin assembly in pulley hub bore. Place support block under staking pin. Reposition staking pin after each impact. Stake should be formed down to but not touching bearing. Stake at 3 equally-spaced points around bearing.

Install Pulley & Bearing Installer Tool (Reference No. 1-Holding Fixture, No. 13-Pulley & Bearing Installer, No. 14-Puller Pilot.). Scheme 100

With compressor still mounted in holding fixture, place pulley and bearing assembly on front head. Position the pulley and bearing installer and puller pilot directly over inner race of bearing. Install a puller as shown.

Install Pulley & Bearing. Scheme 101

Tighten puller center screw to force pulley and bearing assembly onto compressor head. Be sure proper alignment is maintained throughout installation.

Install Snap Ring - Tool No. 6-External Snap Ring Pliers. Scheme 102

Using external snap ring pliers, install snap ring which retains pulley and bearing.

Install Key. Scheme 103

Clean shaft and install shaft key. Allow key to project 1/8" from keyway. Key is curved slightly to provide an interference fit with hub keyway. Perform steps 18-20 of "SEAL REPLACEMENT".

Remove Clutch Coil - Tool No. 14-Puller Pilot, No. 16-Puller Legs. Scheme 104

Perform steps 1-3 of "PULLEY BEARING REPLACEMENT". Install puller and puller legs as shown. Tighten forcing screw against puller pilot. Lift off clutch coil.

Align Clutch Coil - Tool No. 15-Clutch Coil Installer. Scheme 105

Align clutch coil terminals with indentation in compressor head. Place coil installer over internal opening of clutch coil housing. Align installer, coil, and front head.

Install Clutch Coil. Scheme 106

Install puller as shown, with crossbar in countersunk center hole of clutch coil installer. Turn center forcing screw, while keeping clutch coil properly aligned.

Stake Clutch Coil. Scheme 107

When clutch coil is properly seated on front head, use a 1/8" diameter drift punch to stake front head at 3 equally-spaced locations. Stake size should be half the area of drift tip, and .010-.015" deep. Perform steps 7-10 of "PULLEY BEARING REPLACEMENT."