Doing some maintenance on my 05 525 EFIs with 250 hours. Changed the original fuel filters and used GF652 AC Delco after doing a search on OSO. I was getting pressure leaks after install so snugged up the fittings and that took care of port engine. Starboard could not get it to stop leaking so changed out to another filter, all good. Went to launch boat and after engines fired both pissing fuel between fittings and lines. Snugged up both again, no fix so changed both filters again and port was good starboard still leaking. I tried a Purolator equivalent from the parts store on starboard and still leaking. I am locating the lines in the filters and then hand tightening the fittings, then I use a wrench on a fitting and one on the filter and tighten snug, do the other side then check for leaks before installing mounting bracket. Pretty basic but still leaking. Any help would be appreciated!

that is a pretty common problem we install copper sealing washers in the flare joint seals them right up ,most hydraulic shops have them

Thank you for the tip!

This just happened to me on 2005 500 EFI's. Really pissed me off, even using Merc Racing filters from Teague.

I used copper washers and problem fixed. Must be copper so they seal is the trick. +1 to MDG for sharing the info.

Been through this too... PITA! If you cant get the copper washers, I had good luck using some valve grinding compound in the flare. I snugged it up by hand and rotated the filter on the line to true things up. Took it apart, wiped it clean and it sealed right up.

Depending on what fuel U use because you might be surprised about what that cooper washer might look like down the road, plus you just added a form of dissimilar metal in contact with each other in which promotes corrosion. Just saying

I totally recommend plus have been using Gasoila sealant for 25 years and running. The motorcycle crowd from the 1960's on up that had fuel leaks swear by this stuff and so do I. Many marine gas tanks especially the portable gas tanks use to recommend this stuff as well when installing fuel barbs in their gas tanks. FYI.