New seals. They are cheap and will prevent future problems. I buy them by the bag (since I go through so many pipes) from "Shovelhead" on eBay.
There are two types; The flat ones and the cone shaped ones. Many like the "Screaming Eagle" cone shaped ones but in my experience there compress too much and interfere with he opening. I like the simple flat ones and as Blitz as stated here before if you have a weak connection just double up on the seals.
Later,
Ray