And how many `gingerbeers` would check the tyre pressure before replacing a missing valve cap ??
Guilty as charged milud.
Tech log certified as such too.
All this confusion between bicycle tyres, schraeder valves and the humble aircraft tyre.
Bicycle tyre dust cap, plastic, cheap, keeps the dirt out and protects the thread. Same on my car.
Someone somewhere must have it in writing as it was drummed into us for years that the Valve Cap (on an aircraft wheel) is the Primary seal.