I've noticed many used fuel injectors for sale on ebay stating new orings, caps, and filter screens. How do you replace the filter screens in the injectors without destroying them? I tried on a few old injectors that I had and I literally destroyed the filter and the injector! Then I went to a couple of local auto suppliers and they didn't even have a listing for the filters. Is there a special tool and/or technique in removing them for cleaning purposes? And is this a factory item? I normally clean them by soaking the injectors in a cleaner overnight then back flushing them by blowing compressed air while energizing the terminals. Thanks for any replies.

Mike