Fuel Cap

Replace the fuel filler cap on a 1992 Dodge Viper, including inspection of the cap tether and filler neck seal.

Warnings

Tools required

Parts

• Fuel filler cap × 1 — OEM or equivalent vented cap
• Fuel cap tether (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine to cool if recently driven to minimize fuel vapor exposure
3. Open fuel filler door located on left rear quarter panel

Procedure

1. 1

   Remove existing fuel cap
   Turn the fuel cap counterclockwise until it releases from the filler neck threads. The cap should release after approximately 2-3 turns. Note any difficulty turning or unusual resistance, as this may indicate cross-threading or filler neck damage.
2. 2

   Inspect cap tether
   Determine whether your cap is tethered; many 1992 Viper caps are not. If a tether is present, examine it for cracks, fraying, or detachment points and inspect its anchor point on the filler assembly. If a tether is damaged and replacement is needed, access to the mounting point may require removal of the filler door trim panel.
3. 3

   Inspect filler neck seal
   Use a flashlight to inspect the rubber seal inside the filler neck opening. Look for cracks, deterioration, or fuel staining that would indicate leakage. Wipe the seal area with a clean rag to remove any dirt or debris. The seal should be pliable and intact with no visible damage.
4. 4

   Check cap venting
   Examine the old cap for the pressure relief mechanism. The 1992 Viper cap incorporates a venting feature; inspect the underside of the old cap to identify its vent/relief mechanism. Verify the new replacement cap has the same venting feature, as a non-vented cap will cause fuel system pressure issues and potential fuel tank deformation.
5. 5

   Install new fuel cap
   Thread the new fuel cap clockwise onto the filler neck until it seats firmly. Continue turning until you hear or feel 2-3 clicks, which indicates proper sealing engagement. Do not overtighten past the clicking point, as this can damage the cap ratchet mechanism or filler neck threads.
6. 6

   Test cap operation
   Remove and reinstall the cap once more to verify smooth threading and proper clicking engagement. The cap should turn freely without binding and should not wobble when fully tightened. If the cap is equipped with a tether, verify it allows the cap to hang freely without strain when removed; note that many 1992 Viper caps are not tethered.

Reassembly

1. Close fuel filler door and verify it latches securely
2. If a check engine light was present due to the faulty cap, it may take 1-3 drive cycles for the ECM to clear the evaporative system codes

Verification

• Verify fuel cap clicks 2-3 times when tightened and sits flush with filler neck
• Check that cap tether functions properly and does not bind
• Start engine and check for any fuel odor around filler door area
• Monitor for check engine light after several drive cycles to confirm no evaporative system leak codes

More procedures for this vehicle