If the car is not a show car but a driver like mine, I'd look into installing a 1/4" ball valve instead of the original type. I've had no trouble with either car I have done that with. On another car, I used this kit
https://www.snydersantiqueauto.com/p...9345&cat=41707 and had no more trouble with that one.
I got to thinking about that little capsule of gas proof grease they include in that kit. I pondered for ages over what they used but everything I tried dissolved in gas. Then, it hit me. We need a lubricant that is water based, not the product of an barrel of oil. There was only one other application I could think of where that was important. I haven't tried it yet but I reckon a dab of KY lube would do the trick. I haven't gone to the trouble of buying some to test just in case my wife finds it!!!!