fuel

Fuel Cap

for 2007 Ram 3500 5.9L I6 Cummins · 4WD

Difficulty

Easy

Time

18 min

Tools

Steps

✓Fact-checked. Built from OLP's spec database, then independently fact-checked line by line with every correction applied. Master-tech sign-off by Chris Hackleman is queued. Cross-check torque values against the factory manual, and stop if anything looks unsafe. How our data is made.

This procedure covers the removal and replacement of the fuel filler cap on a 2007 Ram 3500 with 5.9L Cummins diesel engine.

Warnings

⚠Ensure vehicle is parked on level ground away from ignition sources before opening fuel system

ℹ️The fuel cap on diesel models may have residual fuel or vapors; have a clean towel ready

Tools required

Clean shop towel

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Parts

Fuel filler cap × 1 — OEM Mopar tethered fuel cap or aftermarket equivalent

As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.

Preparation

Park vehicle on level ground and turn off engine
Allow fuel system to cool if vehicle was recently operated
Locate fuel filler door on driver side rear quarter panel

Procedure

1
Open fuel filler door
Press on the rear edge of the fuel filler door on the driver side rear quarter panel to release the spring-loaded latch and open the door fully.
2
Remove existing fuel cap
Grasp the fuel cap firmly and rotate counterclockwise (left) until it releases from the filler neck threads. The cap is tethered to the fuel door and will remain attached. If the cap is stuck, ensure you are turning in the correct direction and apply steady pressure without forcing.
3
Inspect filler neck
Examine the fuel filler neck threads for damage, debris, or corrosion. Clean any debris from the threads using a clean shop towel. Check the tether attachment point on the fuel door to ensure it is secure.
4
Install new fuel cap
Align the new fuel cap with the fuel filler neck opening and ensure the threads are properly started. Rotate the cap clockwise (right) until it clicks or tightens firmly. Do not over-tighten; most OEM caps will click or ratchet when properly seated.
5
Verify cap installation
Gently tug on the fuel cap to ensure it is fully seated and secure on the filler neck. The cap should not feel loose or rotate freely. If equipped with a tether, verify the tether is properly attached and allows the cap to reach the filler neck without strain.

Reassembly

Close the fuel filler door firmly until it latches
Verify the fuel filler door sits flush with the body panel

Verification

Start the engine and verify no check engine light illuminates for fuel cap or EVAP system codes
Visually inspect the fuel cap area for any fuel odor or vapor leakage
After driving, confirm the check engine light does not illuminate with fuel system or evaporative emission codes (P0440, P0455, P0457)

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