Stubborn fuel filter

Alright... I'm on my second day of trying to get his stupid thing off my 98 Tahoe, and I'm getting frustrated. I know I waited too long, it's been about 18 mo. since it was replaced last. It was last serviced by a dealership down in SC when my fuel pump went out while on vacation. I think they may have overtightened it, but the flare nuts on both ends are obviously gettting more corroded with age also. If I ever do get this off, I know I'll be putting some anti-seize on the threads!

I was able to loosen the rear fitting, but can't get the other to budge. I have been soaking it good with Kroil and PB Blaster penatrating oil for the last two days. I am only using a flare nut wrench so far, but it is dangerously close to rounding off the hex. I hate to use a vise grip or some other locking pliers, because that usually destroys the nut. Any other tip or suggestions for stubborn flare fittings? Please don't say "use the torch" because I am probably mad enough to do it!

It's out! :) Man, that was by far the most stubborn one I have ever had though. I did finally have to use a vise grip on it, but just to break it loose so it is still fairly decent. I also rapped on it several times with a piece of pipe and a hammer, so maybe the impact of that helped loosen the bond also.

I did apply a small amount of anti-seize to the threads when I put it back together, and was carefull not to tighten any more than necessary. Chalk this one up as a lesson learned for me... I'll be changing the filter every 15k religiously from now on. That fuel coming out of the old one was black as charcoal!

Just wanted to add something another member pointed out. He said that "if you are using SAE standard flare wrenches instead of even open end metric you will do more damage than good."

Even though I knew the fitting was metric, I thought I was OK using a 5/8 flare cause I thought it was close enough... Bad decision on my part! I knew there was a metric size that was equal to 5/8, but I think I was off by 1 mm. Now that I just did the math for a standard 15mm nut, 5/8" is about .035" bigger. Enough to damage the nut for sure! I think this would have helped tremendously if I would have gotten a 15mm flare wrench on it right away. My next trip to the hardware store I get a set!

Whatever you do, just don't take a propane torch to it like I did, I got the bolt off, but I had to rewire EVERYTHING! For some reason those front ones are a bitch to always get off but yeah, I ended up going with a vice grips too, and because of that I'll have to use that from now on. Next time though I think I'll change to a different type of filter and get all new fuel lines, even though new lines are expensive as hell. I think it's like 100 bucks a line, and there are essential, what 6 lines or something? There are three that lead up front, and 2 or 3 coming form the back too.

Another good tip to keep the fittings from rusting up too much is to spread a nice thick coat of multipurpose grease on them. It sticks, it waterproofs the area, and it keeps those fittings nice and lubed. It should make changing the filter a breeze next time. Just a trick Ole Man Lalonde taught us. Later. M.

A couple of weeks ago I had the same problem on the same fitting as everyone else. I basically destroyed the front flare nut by using vise grips. After a week of daily soaking in Kroil I finally was able to remove it. The threads were still good despite the badly rounded nut. I made sure to put anti-sieze on them and covered the joint with grease as the previous poster suggested.
I will be replacing the filter at least annually bacause I hate spending an hour on what should be a five minute job!:banghead:

would be nice to have D.I.Y. stickies for various repairs or installs. :\