🔧 GLC - Fuel Cap Replacement

Replacing the fuel cap is a quick job: you remove the old cap from the filler neck and install a new, correct-sealing cap. A good cap prevents fuel vapor leaks and can fix or prevent an EVAP-related check engine light caused by a weak seal.

Difficulty Level: Beginner | Estimated Time: 0.1-0.3 hours

---

⚠️ Safety & Precautions

• ⛽ Turn the engine off and keep the key/fob away from the vehicle while working at the fuel door.
• No smoking, flames, or sparks near the fuel filler area.
• Work in a well-ventilated area and avoid breathing fuel vapors.
• Wipe up any spilled fuel immediately and dispose of rags safely.
• Battery disconnect is not required for this repair.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Nitrile gloves
• Safety glasses
• Clean shop rag

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Fuel filler cap (correct for GLC) - Qty: 1

---

📋 Before You Begin

• Park on level ground, shift to Park, and shut the engine off.
• Let the area around the fuel door cool down if the vehicle was just driven.
• Open the fuel door and use a clean shop rag to wipe dust away from the filler area so dirt doesn’t fall into the neck.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Open the fuel door

• Use your hand to open the fuel door.
• Put on nitrile gloves and safety glasses.

Step 2: Remove the old fuel cap

• Grip the cap and turn it counterclockwise until it comes free.
• If your cap has a tether (the small strap that keeps it attached), let it hang—don’t pull hard on it.
• Tip: Keep the cap opening facing up.

Step 3: Inspect and clean the sealing surfaces

• Use a clean shop rag to wipe the filler neck lip (the round surface the cap seals against).
• Check the old cap’s rubber seal for cracks, flattening, or missing pieces—this is a common cause of EVAP leaks.

Step 4: Install the new fuel cap

• Thread the new cap on by hand (clockwise).
• Keep turning until it fully seats and you feel it tighten firmly. Do not use tools to tighten it.
• If equipped with a tether, make sure it’s not twisted and isn’t pinched by the fuel door.

Step 5: Close the fuel door

• Close the fuel door and press it gently until it latches.
• Use the clean shop rag to wipe any fingerprints or fuel residue.

---

✅ After Repair

• Start the engine and check that there’s no fuel smell around the fuel door area.
• If you replaced the cap because of a check engine light, it may take a few drive cycles for the EVAP monitor to run and the light to clear on its own. If the light stays on, the system may have another leak.

---

💰 DIY vs Shop Cost

Shop Cost: $40-$120 (parts + labor)

DIY Cost: $15-$50 (parts only)

You Save: $25-$70 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.2-0.5 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.