🔧 GS - A/C Compressor Replacement

Replacing the A/C compressor on your GS means safely recovering the refrigerant, removing the drive belt and compressor, then reinstalling and evacuating/recharging the system. The “must-do” part is pulling a deep vacuum and recharging by weight—otherwise cooling performance and compressor life can suffer.

Difficulty Level: Advanced | Estimated Time: 4-7 hours

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⚠️ Safety & Precautions

• ⚠️ Refrigerant is hazardous and illegal to vent—recover it with proper equipment.
• ⚠️ Wear safety glasses and gloves; liquid refrigerant can cause frostbite.
• ⚠️ Work on a cool engine; keep hands clear of the belt drive path.
• ⚠️ Support the car on jack stands; never rely on a jack alone.
• ⚠️ Battery disconnect recommended before unplugging compressor wiring.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Metric socket set (8mm-19mm)
• 3/8" drive ratchet
• 6" extension (3/8" drive)
• Torque wrench (10-100 Nm range)
• Trim clip removal tool
• Flat blade screwdriver
• Serpentine belt tool (specialty)
• Line wrench set (10mm-17mm)
• Pick tool set
• Shop towels
• A/C manifold gauge set for R134a (specialty)
• Refrigerant recovery machine (specialty)
• Vacuum pump (specialty)
• Refrigerant scale (specialty)
• Infrared thermometer (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• A/C compressor - Qty: 1
• A/C compressor oil (ND-OIL 8 / PAG equivalent for your system) - Qty: 1
• A/C line O-ring set - Qty: 1
• R134a refrigerant (charge amount per under-hood label) - Qty: 1
• Serpentine belt - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and chock the rear wheels.
• Recover the refrigerant using a refrigerant recovery machine (this is the machine that pulls refrigerant into a storage tank).
• Disconnect the negative battery terminal using a 10mm socket.
• Raise the front and support the car on jack stands placed at proper lift points.
• Tip: Take photos of routing and connectors.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Recover the refrigerant

• Connect the A/C manifold gauge set for R134a (specialty) to the high/low service ports.
• Use the refrigerant recovery machine (specialty) to fully recover the refrigerant from the system.
• Once recovered, shut off valves and disconnect the equipment.

Step 2: Remove the undercovers for access

• Use a trim clip removal tool and 10mm socket to remove the front engine under cover/splash shields.
• Set clips/bolts aside in a tray so you don’t lose them.

Step 3: Remove the serpentine belt

• Note the belt routing (snap a photo).
• Use a serpentine belt tool (specialty) to rotate the belt tensioner and slip the belt off the A/C compressor pulley.
• If the belt is cracked/glazed, plan to replace it.

Step 4: Disconnect the compressor electrical connector

• Locate the compressor connector and release the lock tab using a flat blade screwdriver (gently).
• Unplug the connector and tuck it out of the way.

Step 5: Disconnect the A/C lines from the compressor

• Place shop towels under the compressor to catch any oil.
• Use the correct-size line wrench set (10mm-17mm) to loosen the refrigerant line fasteners/fittings.
• Remove the lines and immediately cap/cover the open ends (use shop towels) to keep moisture out.
• Remove old O-rings using a pick tool set (do not scratch metal sealing surfaces).
• Tip: Moisture is the enemy of A/C systems.

Step 6: Unbolt and remove the compressor

• Support the compressor with one hand.
• Use a metric socket set (8mm-19mm), 3/8" drive ratchet, and 6" extension (3/8" drive) to remove the compressor mounting bolts.
• Remove the compressor from the bottom of the engine bay.
• When reinstalling mounting bolts, Torque to factory specification using a torque wrench.

Step 7: Set oil amount for the new compressor

• Drain the old compressor oil into a measuring container (use shop towels to prevent spills).
• Add the same measured amount of correct oil into the new compressor using A/C compressor oil (ND-OIL 8 / PAG equivalent).
• Rotate the new compressor hub by hand a few turns to distribute oil (if applicable).
• Tip: Too much oil reduces cooling.

Step 8: Install the new compressor

• Position the compressor and hand-start all mounting bolts.
• Tighten using a metric socket set (8mm-19mm) and 3/8" drive ratchet.
• Torque to factory specification using a torque wrench.

Step 9: Reconnect A/C lines with new O-rings

• Lightly coat new O-rings with the correct oil using A/C compressor oil (ND-OIL 8 / PAG equivalent).
• Install O-rings and reconnect the lines.
• Tighten line fasteners/fittings using a line wrench set (10mm-17mm).
• Torque to factory specification using a torque wrench (if the fastener style allows torque measurement).

Step 10: Reinstall the serpentine belt

• Route the belt correctly using your photo.
• Use a serpentine belt tool (specialty) to rotate the tensioner and slide the belt fully onto the pulleys.
• Visually confirm the belt is centered on every pulley groove.

Step 11: Reinstall undercovers and reconnect battery

• Reinstall splash shields using a trim clip removal tool and 10mm socket.
• Reconnect the negative battery terminal using a 10mm socket.

Step 12: Evacuate and recharge the A/C system

• Connect the A/C manifold gauge set for R134a (specialty).
• Pull a deep vacuum using a vacuum pump (specialty) (this removes air and moisture).
• Verify vacuum holds (no leak) before charging.
• Charge refrigerant by weight using a refrigerant scale (specialty) and R134a refrigerant.
• Use the exact charge amount shown on the under-hood A/C label.

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✅ After Repair

• Start the engine and turn A/C to MAX; confirm the compressor engages and the radiator fans operate.
• Check for leaks at the compressor line connections (look for oil residue and listen for hissing).
• Use an infrared thermometer (specialty) at the center vent to confirm vent temps drop steadily.
• Recheck belt alignment after a short test drive.
• Tip: Weak cooling often means under/overcharge.

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💰 DIY vs Shop Cost

Shop Cost: $1,200-$2,200 (parts + labor)

DIY Cost: $350-$900 (parts only)

You Save: $850-$1,300 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 3-5 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.