What product for rusty fuel filter threads?

[901Memphis]

I went to do the fuel filter on my Buick and it wouldn't budge. The threads on the nut are too rusty. The fuel line threads are a bit rusty too.

Going to need some penetrating oil I suppose should I just use some WD40 or buy something else? I think that's all I have on hand but it wasn't in my trunk and I will have to do the job another day.

 

[renegade_987]

I use Liquid Wrench Penetrating Oil on rusty bolts and nuts. Works great!

 

[robl]

PB Blaster has worked well for me.

 

[Robenstein]

WD40 is not a good penetrating oil. As mentioned liquid wrench is a really good one that can be found all over. A hot rod magazine tested a bunch and the top two were Kroil followed by an old timers mix of 50/50 acetone and ATF. Liquid wrench came in third.

 

[NHGUY]

Cut them off and buy the Dorman repair ends.

 

[Wolf359]

In terms of good penetrating oils, after liquid wrench, there'd be PB Blaster which you can find in stores, but AeroKroil gets really good reviews, but you usually have to mail order it either directly from the manufacturer or from Amazon. I think direct gets you a buy one get one free offer.

 

[440Magnum]

PB Blaster, or Kroil if you want the absolute best. You can buy PB at most parts stores, Kroil you gotta buy from Kano Labs.

 

[dishdude]

I think I'd leave it alone.

 

[901Memphis]

Maybe if I posted a picture we can gauge how bad it is.

I mangled the old filter a little, I'm surprised it didn't leak after I reattached it. I already have the AC Delco fuel filter and I bought it a long time ago from rockauto so I don't want to return it.

Even though I pulled the fuel pump fuse and ran til it died then tried to keep cranking it a little more to relieve pressure it still spewed pressurized fuel in the pan I had down and dripped for a long time before I wrapped it in rag.

Either way rust is killing my cars appearance, I'll update tonight with pictures.

 

[Trav]

Try something like evaporust or bullfrog on the threads for a few days, you will have to keep it wet which is a PITA.
It might remove or soften enough of the rust and give the penetrating oil a better shot of doing something.

Whatever you do get the penetrating oil down the line and tap it with a small hammer lightly and repeatedly so it wicks its way down and frees the line from the nut.

 

[deanm11]

I had the same basic issue on my '99 Regal. Rusty and actually leaking fuel filter. My car was garaged most of its life but things are starting to rust out. The fuel filter was 4-5 years old. I used PB blaster but I think the key was to get a line wrench on the flare nut up against the unibody & then I used the 20mm wrench and turned the filter can itself instead of the line/flare nut. I was stuck and almost gave up.. then I just gave it a bit more effort, confident in the the line being backed up to the body and I wouldn't twist the line... it gave. This would be while the back end/hose is disconnected.

 

[andyd]

Yah, If you can back the nut up with an anvil, plate piece, big nut so you dont mangle the lines and tap as many flats of the nut that you can. I used this when I was harvesting brake lines from an ABS unit. They were in an easy spot to whack with a hammer. Most loosened with out much hassle.

 

[eljefino]

+2. Is it threaded on one end and a quick connect on the other? The quick connect will spin forever.

Just lock the line nut with a big open end wrench, flare wrench, vise grips, what have you. Then unscrew the filter itself from the fuel line. Use a bigger vise grips, maul the can, pipe wrench, whatever. Remember residual pressure, this will be messy.

Usually the rust is such that the nut will break the metal line, but the filter will unthread from the nut with a moderate level of effort.

The quick connects are fun but the new filter comes with a new connector, so maul the other one however you need to.

 

[artificialist]

Use PBblaster, and hope for the best.

Usually if a line is rusted, it will break away, and you will need to make a new one.

 

[Vikas]

You will not believe me but my mechanic used blue wrench on the Toyota Camry fuel filter! I recall he took the assembly out from the car, filled the filter with the water and then torched it to remove some brackets. To be frank, I was little bit too far to watch while he was doing that!

 

[901Memphis]

Here are some pictures of the horror!

You can see why i wanted to get it off of there, am worried about rust through, although i have seen worse .

 

[artificialist]

If you use a cheap flare nut wrench, it may round off the head of the nut. If you use an high quality flare nut wrench, you might be able to remove the nut and install it on the replacement part.

I would suggest also to hold the filter with a good flare nut wrench.

Also, Wix usually sells fuel filters with the bracket already in the package. That is why I prefer Wix fuel filters.

 

[eljefino]

That'll come off. Get the bracket loose and the quick connect off then you can gently bend the line a foot or so back to get the filter down a few inches so you can work it. Stick a vise grips on the line nut and make that stationary, then use an open end wrench, vise grips, pipe wrench etc on the filter's nut, or the filter itself, and spin it off.

Also pay attention to that line behind it-- looks like the fuel return line, and it's starting to look rusty. Could also be the EVAP line.

I went through this on my W-body Century and just ran new vinyl fuel line. Expensive but the way it should have been done from the get-go. The expense was in the connectors and doo-dads.

 

[Trav]

Thats not rusty thats normal in the salt belt.
Penetrating oil, remove the bracket bolt and spin that filter right off by just holding the line nut with a flair nut wrench and a big wrench on the filter, turn the filter then free the nut once its apart.

The plastic connector is no problem. Make sure you spray penetrating oil up in the rail where the nut for the bracket is or you will be drilling it out.
Spray the evap lines with rust preventative.

I was expecting to see a real rusty one with real crispy lines.

 

[The_Eric]

eljefino is right, that'll come off fine- I've had WAY worse than that come off.


Get a 16mm flare nut wrench (or a 5/8" should work too) and any old 20mm wrench and crank on it. Offset the wrenches slightly so that you can wrap your hands around both of them and squeeze the together. (instead of trying to hold/twist them while they're spread way apart) This will give you lots of control and leverage.

Personally I try to avoid spinning the filter off the nut, because there is an o-ring in there that can get snarfed by the filter spinning around it. If it does come to that, make sure you lube or grease it upon assembly.