My ‘74 GMC gas fill door would have had a magnetic catch riveted (ok, nut riveted) to the top of the fill door cavity. Unfortunately, it was removed likely back in the ‘70’s when California mandated these enormous tank fill nozzles (they call them sleeves - see image below) at gas stations. So when it rains, water washes through that gas tank fill area and ends up rusting the lock cylinder on the locking gas cap.
I purchased a new locking gas cap and decided I would attempt to resolve the water issue. Yes, I need to install the magnetic catch on the right side of the door but that doesn’t stop water from entering the fill door cavity.
While on eBay one afternoon, I found a new Porsche 356 gas flap for the fuel door. I purchased the item last July for $21 and installed it this afternoon and it seems to have solved the problem. It has what looks like vinyl on one side and black foam on the other side.




I purchased a new locking gas cap and decided I would attempt to resolve the water issue. Yes, I need to install the magnetic catch on the right side of the door but that doesn’t stop water from entering the fill door cavity.
While on eBay one afternoon, I found a new Porsche 356 gas flap for the fuel door. I purchased the item last July for $21 and installed it this afternoon and it seems to have solved the problem. It has what looks like vinyl on one side and black foam on the other side.




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