I just got done doing a fuel pump install via the trap door method. I would greatly recommend the trap door thus far. I was not looking forward to going to all the hassle of replacing the pump the conventional way. I read about the trap door method last night and it took me about an hour and a half and it was up and running again. Question is: I took it for a drive around the block before covering up the cutout and there was a hissing/whirring sound from the pump area. I was wondering if that is just the natural pump sound that you usually can't hear because of the floor or if air might be leaking in. I made sure the o-ring was seated as well as could be I thought. I dunno, if someone could clear that up I would appreciate it. Thanks!