🔧 Impreza - A/C Compressor Replacement

Replacing the A/C compressor on your Impreza is a mix of mechanical work (remove/replace the compressor) and HVAC service work (recovering, evacuating, and recharging refrigerant). The most important part is doing it legally and safely—refrigerant must be recovered with proper equipment, and the system must be vacuumed and recharged by weight.

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

---

⚠️ Safety & Precautions

• 🛑 Do not vent refrigerant to the air—have the system professionally recovered first.
• 🧤 Wear safety glasses and gloves; liquid refrigerant can cause frostbite instantly.
• 🔥 Work on a cool engine; the radiator and exhaust area can burn you.
• 🔌 Disconnect the negative battery cable before unplugging the compressor.
• 🧼 Keep dirt out of A/C lines—cap/plug openings immediately after disconnecting.

---

🔧 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
• 10mm socket
• 12mm socket
• 14mm socket
• 3/8" drive ratchet
• 6" socket extension
• Torque wrench (10–100 ft-lbs range)
• Trim clip tool
• Flathead screwdriver
• Serpentine belt tool or 14mm wrench
• Line wrench set (10mm–17mm)
• Pick set
• Shop rags
• Caps/plugs for A/C lines (specialty)
• A/C manifold gauge set (specialty)
• Vacuum pump (specialty)
• Refrigerant scale (specialty)
• Refrigerant recovery machine (specialty)

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• A/C compressor - Qty: 1
• A/C compressor O-ring set - Qty: 1 set
• Receiver/drier or desiccant element (if serviceable separately) - Qty: 1
• A/C refrigerant (per under-hood label type and weight) - Qty: 1
• A/C compressor oil (per under-hood label spec) - Qty: 1

---

📋 Before You Begin

• Park on level ground, set the parking brake, and chock the rear wheels.
• Have the refrigerant recovered first (most shops can do “recover only”).
• Open the hood and take a photo of the under-hood A/C label (it lists refrigerant type and charge weight).
• Disconnect the negative battery cable using a 10mm socket.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Recover the refrigerant (required)

• Use an A/C refrigerant recovery machine (specialty) to fully recover the refrigerant from the system.
• If you don’t have recovery equipment, schedule a shop to recover it before you start disassembly.

Step 2: Raise the front of the car and remove the lower covers

• Lift the front with a floor jack (rated 3-ton minimum) and support it on jack stands (rated 3-ton minimum).
• Remove the engine under cover/splash shield using a trim clip tool, flathead screwdriver, and 10mm socket as needed.

Step 3: Remove tension from the A/C drive belt

• Use a serpentine belt tool or 14mm wrench to rotate the belt tensioner and slip the belt off the A/C compressor pulley.
• Take a quick belt routing photo.

Step 4: Disconnect the compressor electrical connector

• Locate the compressor connector and unplug it by hand.
• If the lock tab is stubborn, use a pick set gently to release it (a pick is a small hooked tool for releasing clips).

Step 5: Remove the refrigerant lines from the compressor

• Place shop rags under the fittings to catch any oil drips.
• Use the correct size line wrench to loosen the A/C line fittings/bolts at the compressor (a line wrench grips more sides than an open-end wrench to prevent rounding).
• Immediately cap the open lines and compressor ports using caps/plugs for A/C lines (specialty) to keep moisture and dirt out.
• Remove and discard the old O-rings using a pick set.

Step 6: Remove the compressor mounting bolts and compressor

• Support the compressor with one hand.
• Use a 12mm socket and/or 14mm socket with a ratchet and extension to remove the compressor mounting bolts.
• Remove the compressor from the engine bay.
• Torque note: Reinstall bolts to Torque to Subaru factory specification using a torque wrench. (Exact values vary by fastener/location; I can give the exact numbers if you share a photo of the compressor mounting area and the bolt heads.)

Step 7: Set oil amount in the new compressor (critical)

• Drain the old compressor oil into a measuring cup (use shop rags to stay clean).
• Add the same measured amount of the correct oil into the new compressor.
• Use only the oil type listed on the under-hood A/C label and/or compressor instructions, and do not “overfill.”

Step 8: Install new O-rings and reinstall the compressor

• Lightly coat new O-rings with the correct A/C oil using a gloved finger.
• Install the new O-rings onto the lines/fittings.
• Position the compressor and hand-start all mounting bolts.
• Tighten mounting bolts evenly using a ratchet, then final-tighten with a torque wrench to Torque to Subaru factory specification.

Step 9: Reconnect A/C lines and electrical

• Remove the caps/plugs and reconnect the A/C lines using the correct line wrench.
• Tighten fittings evenly and final-tighten to Torque to Subaru factory specification using a torque wrench (use the correct crowfoot if required).
• Reconnect the compressor electrical connector by hand until it clicks.

Step 10: Reinstall belt and under covers

• Route the belt and use a serpentine belt tool or 14mm wrench to move the tensioner and slip the belt back on.
• Reinstall the splash shield/under cover using a 10mm socket and trim clip tool.

Step 11: Evacuate the system and recharge by weight

• Connect an A/C manifold gauge set (specialty) to the service ports.
• Evacuate with a vacuum pump (specialty) for 30–45 minutes.
• Close valves and verify it holds vacuum (leak check).
• Recharge with the exact refrigerant type and exact weight listed on the under-hood label using a refrigerant scale (specialty).

---

✅ After Repair

• Reconnect the negative battery cable using a 10mm socket.
• Start the engine and turn A/C on MAX, blower high, recirculation on.
• Watch for abnormal noises and verify the A/C clutch/compressor engages normally.
• Use the A/C manifold gauge set (specialty) to confirm pressures look normal for the current ambient temperature.
• Check for oily residue around fittings (a common sign of a slow leak).

---

💰 DIY vs Shop Cost

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

DIY Cost: $300-$900 (parts only, assuming you already have A/C equipment)

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

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.5-4.0 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.