fuel
Fuel Cap
for 1970 AMC Rebel Machine 390ci V8 · RWD
Editorial review:Chris Hackleman — Master Technician · 20+ years
Difficulty
Easy
Time
12 min
Tools
1
Steps
5
✓Expert-verified. Personally reviewed and approved by OLP's master technicians (Chris Hackleman — 20+ years each). Always follow the vehicle's factory service information and torque specs.
Replacement of the fuel cap on a 1970 AMC Rebel Machine to ensure proper fuel system sealing and vapor control.
Warnings
⚠️Perform this procedure in a well-ventilated area away from open flames, sparks, or heat sources due to fuel vapors.
⚠Do not perform this procedure immediately after running the vehicle - allow fuel system to cool and pressure to normalize.
ℹ️The 1970 Rebel Machine uses a vented fuel cap design - do not substitute with a non-vented cap as this will cause fuel system issues.
Tools required
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Parts
- Fuel cap × 1 — Use OEM specification or equivalent vented cap
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 ensure ignition is off
- Allow fuel system to cool if vehicle was recently operated
- Ensure replacement fuel cap is the correct vented type for 1970 AMC application
Procedure
- 1Locate fuel filler capThe fuel filler cap is located on the driver's side rear quarter panel behind the hinged fuel door. Open the fuel door by pressing on the rear edge to release the spring-loaded hinge.
- 2Remove old fuel capTurn the fuel cap counterclockwise (left) approximately one full turn until it stops. You should hear a slight hiss as any residual vapor pressure equalizes. Continue turning counterclockwise and lift the cap away from the filler neck.⚠If fuel has been sloshing or tank is very full, have a shop rag ready to catch any fuel that may overflow from the filler neck.
- 3Inspect filler neck seal surfaceExamine the top of the fuel filler neck for debris, corrosion, or damage to the sealing surface. Wipe clean with a shop rag if dirt or debris is present. Check that the spring-loaded flapper valve inside the neck (if equipped) moves freely.
- 4Inspect old fuel cap gasketExamine the rubber gasket on the old fuel cap. Look for cracks, hardening, fuel degradation, or permanent compression marks. This inspection confirms whether cap replacement was necessary and validates the new cap's gasket condition.
- 5Install new fuel capPosition the new fuel cap onto the filler neck, ensuring it seats properly against the neck opening. Turn clockwise (right) until you feel resistance, then continue turning until the cap clicks or stops firmly. Do not force past the stop point as the cap incorporates a torque-limiting ratchet design.
Reassembly
- Close the fuel filler door by pressing it shut until it latches securely
- Retain the old fuel cap as a spare emergency backup if gasket condition is acceptable
Verification
- Verify the fuel cap is fully seated and locked by attempting to turn it further clockwise - it should ratchet or resist further tightening
- Confirm the fuel door closes and latches properly without interference from the new cap
- Start the vehicle and allow it to idle for several minutes, then check for fuel odor around the filler area indicating vapor leakage
- After the next refueling, verify no fuel seepage occurs around the cap threads or gasket