How does a plastic compression fitting go together?
The toothed bit will be what prevents the (presumably) tube from being blown out. The “plastic bit” is probably a washer that fits between the toothed bit and the “O” ring, to protect it. The “O” ring should be the last part fitted. I am having to do a lot od assuming, but first on the tube should be the nut or screwed part, next the toothed bit, then the “plastic bit”, then the “O” ring. If you intend to use the original toothed bit etc., you may not get good results. These sort of components are designed for single use only.
