🔧 RDX - A/C Compressor Replacement

Replacing the A/C compressor means safely recovering the refrigerant, removing the old compressor, installing the new one with new seals, then vacuuming and recharging the system to the exact factory amount. This job is very doable, but the refrigerant handling and recharge steps require A/C service equipment for a reliable, cold A/C system.

Difficulty Level: Advanced | Estimated Time: 3-6 hours

Assumption: Your RDX uses R-134a refrigerant.

---

⚠️ Safety & Precautions

• ⚠️ Refrigerant is hazardous and under high pressure—do not vent it to air; have the system professionally recovered first.
• ⚠️ Wear eye protection and gloves—liquid refrigerant can cause frostbite.
• ⚠️ Keep hands/tools clear of the belt path; the engine cooling fans can start unexpectedly.
• ⚠️ Disconnect the battery negative cable before unplugging the compressor clutch/solenoid connector.
• ⚠️ If the old compressor failed loudly or seized, the system may be contaminated—flush and replace the condenser/receiver-drier as required to prevent repeat failure.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Wheel chocks
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Metric socket set (8mm-19mm)
• 3/8" drive ratchet
• 3/8" drive torque wrench (10-100 ft-lbs range)
• 6" socket extension (3/8" drive)
• 12mm socket
• 14mm socket
• Flat trim clip tool
• Phillips screwdriver
• Serpentine belt tool (14mm) (specialty)
• A/C manifold gauge set for R-134a (specialty)
• Refrigerant recovery machine (specialty)
• Vacuum pump (specialty)
• Refrigerant charging scale (specialty)
• UV leak detection light (specialty)
• Shop rags
• Drain pan

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• A/C compressor (new) - Qty: 1
• A/C compressor clutch/coil (if not included with compressor) - Qty: 1
• A/C line O-ring seal kit (HNBR green) - Qty: 1
• PAG A/C compressor oil (correct spec for your RDX) - Qty: 1
• R-134a refrigerant - Qty: As required (charge by under-hood label)
• Receiver-drier / desiccant (if serviceable separately) - Qty: 1
• A/C condenser (if receiver-drier is not serviceable separately) - Qty: 1 (only if required)
• Serpentine belt - Qty: 1 (recommended if worn or oil-soaked)

---

📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear tires.
• Have an A/C shop (or your own recovery machine) recover the refrigerant before you loosen any A/C lines.
• Open the hood and disconnect the battery negative cable using a 10mm socket.
• Raise the front safely with a floor jack and support with jack stands.
• Remove the lower splash shield using a flat trim clip tool and Phillips screwdriver.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm the system is empty (0 psi)

• Connect the A/C manifold gauge set for R-134a (specialty) to the high and low service ports.
• Verify both gauges read 0 psi before opening any lines.
• If pressure remains, stop and recover refrigerant.

Step 2: Remove the serpentine belt

• Use the serpentine belt tool (14mm) (specialty) to rotate the belt tensioner and relieve tension.
• Slip the belt off the A/C compressor pulley first, then remove it from the other pulleys as needed.
• Inspect the belt for cracks/glazing; replace if needed.

Step 3: Unplug the compressor electrical connector

• Locate the compressor connector near the compressor body and unplug it by hand.
• If there is a lock tab, release it gently using a flat trim clip tool.

Step 4: Remove the A/C suction and discharge lines from the compressor

• Place a drain pan under the compressor area and put shop rags around the fittings.
• Use the correct-size socket from your metric socket set (8mm-19mm) with a 3/8" drive ratchet to remove the line retaining bolt(s).
• Carefully wiggle the lines free—do not pry hard on aluminum tubes.
• Immediately cap/cover the open lines with clean plastic and a rubber band to keep moisture out.
• Remove and discard the old O-rings; you will install new ones.

Step 5: Remove the compressor mounting bolts and take out the compressor

• Support the compressor with one hand, then remove the mounting bolts using a 12mm socket or 14mm socket (varies by bracket) with a 3/8" drive ratchet and 6" socket extension.
• Lower the compressor out carefully without bending nearby lines.
• Set it in the drain pan to catch any oil.

Step 6: Check oil amount and prepare the new compressor

• Drain the old compressor oil into the drain pan and measure what came out (a kitchen measuring cup works well).
• Add the same amount of the correct PAG A/C compressor oil into the new compressor unless the new unit’s instructions specify a different procedure.
• Rotate the new compressor hub by hand a few turns to distribute oil (if it has a clutch/hub you can turn).
• Too much oil can reduce cooling.

Step 7: Install the new compressor

• Position the compressor and hand-start all mounting bolts using your fingers to avoid cross-threading.
• Tighten the mounting bolts using a 3/8" drive torque wrench (10-100 ft-lbs range).
• Torque to factory specification (service manual required).

Step 8: Reconnect A/C lines with new O-rings

• Install new O-rings from the A/C line O-ring seal kit (HNBR green) on each line connection.
• Lightly coat each O-ring with clean PAG A/C compressor oil so it doesn’t pinch.
• Reinstall the lines and retaining bolts using the appropriate socket from the metric socket set (8mm-19mm).
• Tighten using the 3/8" drive torque wrench.
• Torque to factory specification (service manual required).

Step 9: Reconnect the compressor electrical connector

• Plug the connector back in until it clicks into place.

Step 10: Reinstall the serpentine belt

• Route the belt correctly around all pulleys (use the under-hood belt routing diagram if present).
• Use the serpentine belt tool (14mm) (specialty) to move the tensioner and slip the belt onto the last pulley.
• Visually confirm the belt is fully seated in every pulley groove.

Step 11: Reinstall the splash shield and lower the vehicle

• Reinstall the shield using the Phillips screwdriver and flat trim clip tool.
• Lower the vehicle from the jack stands using the floor jack.

Step 12: Evacuate (vacuum) the A/C system

• Reconnect the A/C manifold gauge set for R-134a (specialty).
• Connect the center hose to the vacuum pump (specialty).
• Run the vacuum pump for 30–45 minutes to boil out moisture.
• Close the manifold valves and verify it holds vacuum for 10–15 minutes; if it rises, you likely have a leak.

Step 13: Recharge by weight (not by pressure)

• Place the refrigerant can/tank on the refrigerant charging scale (specialty).
• Add R-134a refrigerant by exact weight per the under-hood label specification.
• Start the engine and set climate to MAX A/C, recirculation ON, and blower HIGH to finish the charge (follow safe charging procedure with the gauge set).

Step 14: Leak check

• Use a UV leak detection light (specialty) if dye is present, or inspect all fittings for oily residue.
• Recheck vent temperature and confirm the compressor cycles normally.

---

✅ After Repair

• Reconnect the battery negative cable using a 10mm socket.
• With the engine running, confirm cold air at the vents and stable idle.
• Listen for belt noise and recheck belt alignment.
• After a short drive, recheck for leaks around the compressor line fittings.
• If the old compressor failed catastrophically (metal debris), plan to replace the condenser/receiver-drier and thoroughly flush lines to prevent repeat failure.

---

💰 DIY vs Shop Cost

Shop Cost: $900-$1,800 (parts + labor)

DIY Cost: $300-$900 (parts only, assuming you can recover/recharge)

You Save: $600-$900 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 3-4 hours.

---

🎯 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.