I purchased 2 PH500XL filters from RockAuto they came in with a nitrile anti drain back valve, I contacted RockAuto, it's going to cost me more to send them back then I paid for them, so I contacted Champ labs, they tell me to contact RockAuto, For a refund because they are RockAuto's supplier.
Another filter that is going downhill, and trying to cut corners.. I bought this filter about 2 months prior, just to cut open and inspect it, and it came with silicone anti drain back valve, which is the last picture..
Another filter that is going downhill, and trying to cut corners.. I bought this filter about 2 months prior, just to cut open and inspect it, and it came with silicone anti drain back valve, which is the last picture..