fuel leak
maybe you have used o-rings with bad quality. I have changed my o-rings several years ago. I went to a rubber local manufacturer and ask him for the best available quality in the right size. He sold me o-rings made of VT 5oo rubber. They are extremly expensive but the best available.
For the tees....if you can get some for a good price....I would change them too, otherwise check the inside for edges.
Jens



