🔧 GLC300 - Cabin Air Filter Replacement

Your A/C and heat pull air through the cabin air filter before it enters the vents. Replacing a dirty filter improves airflow, reduces musty smells, and helps keep dust/pollen out of the cabin.

Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours

---

⚠️ Safety & Precautions

• ⚠️ Turn the ignition OFF and remove the key/fob from the vehicle.
• ⚠️ Be gentle with glovebox/trim clips—forcing parts can crack them.
• ⚠️ No battery disconnect is required for this job.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Trim removal tool (plastic)
• Torx T20 screwdriver
• Torx T25 screwdriver
• Small flat-blade screwdriver
• Flashlight
• Shop vacuum
• Nitrile gloves
• Safety glasses

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Cabin air filter (charcoal/activated carbon recommended) - Qty: 1

---

📋 Before You Begin

• Park on level ground and set the parking brake.
• Move the front passenger seat back for working room.
• Tip: Take a quick photo before removing clips.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Access the passenger footwell area

• Open the glovebox and remove any items so nothing falls out.
• Use a flashlight to look under the glovebox (passenger footwell) for the lower hush panel (the cover under the dash).

Step 2: Remove the under-dash (hush) panel

• Use a Torx T20 screwdriver to remove the visible screws holding the lower panel.
• If there are plastic push-clips, pry the center pin out gently with a small flat-blade screwdriver, then lift the clip out with the trim removal tool (plastic).
• Lower the panel carefully. If a footwell light is attached, unplug the connector by pressing the tab and pulling it off (no tools needed).
• Tip: Support the panel so it doesn’t hang by wiring.

Step 3: Locate the cabin filter cover

• With the panel removed, look upward toward the HVAC housing (the black plastic box under the dash).
• Find the rectangular cabin filter cover. It typically uses small Torx screws or sliding tabs depending on build.

Step 4: Remove the filter cover

• If your cover uses screws, remove them with a Torx T20 screwdriver (some covers may use Torx T25 screwdriver).
• If your cover uses tabs, release them carefully with the trim removal tool (plastic) and/or small flat-blade screwdriver.
• Set the cover and screws aside in a small pile so they don’t get lost.

Step 5: Remove the old cabin air filter

• Wear nitrile gloves and safety glasses.
• Slide the old filter straight out. Keep it level—dirty filters can spill dust and leaves.
• Use a shop vacuum to gently clean loose debris in the filter tray (do not vacuum deep into the blower opening).
• Tip: If you see leaves, vacuum them before installing new filter.

Step 6: Install the new cabin air filter

• Check for the airflow arrow on the filter frame. Install it in the same direction as the old one (the arrow shows which way air flows).
• Slide the new filter in fully so it sits flat and the edges seal.
• If it won’t slide in easily, don’t force it—pull it back out and make sure it’s not tilted or catching on an edge.

Step 7: Reinstall the filter cover

• Refit the cover in the same orientation as removed.
• Install screws using a Torx T20 screwdriver (or Torx T25 screwdriver if applicable) and snug them evenly.
• Tip: “Snug” means tight but not over-tight.

Step 8: Reinstall the hush panel

• Reconnect any unplugged footwell light connector (push until it clicks).
• Position the panel and reinstall screws using a Torx T20 screwdriver.
• Reinstall push-clips: insert the clip body first, then press the center pin in flush using your finger or the trim removal tool (plastic).

---

✅ After Repair

• Start your A/C and fan. Confirm airflow feels stronger and there are no rattles.
• Cycle through vent modes (face/feet/defrost) to ensure everything sounds normal.
• If you had a musty smell, run the fan for a few minutes with A/C on to help dry the evaporator.

---

💰 DIY vs Shop Cost

Shop Cost: $120-$220 (parts + labor)

DIY Cost: $20-$60 (parts only)

You Save: $100-$160 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 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.