You learn something new every day... Answering an eMail question for a fellow, put a gauge on my DeLorean's A/C. Quick connect adapter spit at me when I removed blue cap. And I've lost freon. Appears cap was pressing slightly on shrader valve all this time. Is possibile I mixed brands of adapters/blue caps. Have loosened on all my vehicles to be safe. Just throwing into knowledge pool in case it'll help someone else... Bill Robertson #5939