When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I opened a Cooper this evening that had been on engine I bought.
The by-pass valve is in the dome end. I couldn't tell if the anti-drain back seal is rubber or silicone. I think rubber, but will check tomorrow in better light.