HELP! Fuel line nut rusted, can't remove fuel filter

[theholycow]

On my 2002 GMC, the fuel line nut is rusted to the fuel filter (or maybe to the line; probably both) and I can't free it. I've done lots of whacking with hammers, PB Blaster, Shimano penetrating oil, cold spray, and plenty of brute force.

I've gotten under and sprayed it with the Shimano stuff every day for a week. I just got the PB Blaster today.

I don't think I can reasonably heat it, nor grind off the filter's nut, since I'm working with fuel line.

Any other ideas? It's starting to look like I'll have to replace the fuel line.

[IMBoring25]

If you're seriously looking at fuel line replacement as an option, you could go ahead and remove the old one.

Worst case, you'd have more room to work and could use bigger tools in a more comfortable position.

If you are able to drive the bunny indefinitely while the truck's down, you could even wait until you're sure the gas has all evaporated and use some of those techniques that might involve heat or sparks.

If it doesn't work, fuel line replacement is still an option.

[theholycow]

Now THAT is a good idea. If I've already given up and declared the fuel line dead, I've got nothing to lose; so I could remove the filter and line as an assembly. Then I could work on them while not laying under the truck. I can then drain them, rinse them so there's definitely no fuel in them, and use heat.

I'll have to find out how that's done. As far as I can tell, you can't drop the tank without removing the fuel line; and you can't remove the fuel line without dropping the tank. Catch-22.

[theholycow]

Hooray!

I got it loose! As Slaid Cleaves said in "Drinkin' Days", sometimes you gotta act like you've got a pair. So, I made a bid for the Darwin Awards.

I cut into the fuel filter's nut, slotting it with my dremel's diamond cutoff wheel most of the way to the thread. Some sparks flew but not a lot. I had wiped up the area so there were no pools/drops of fuel around. I couldn't get all the way across the width of the nut but two corner cuts did the job. It wasn't enough to crack the nut but it relieved enough stress on the nut for me to brute-force the nuts until they were persuaded to cooperate.

For how badly it was stuck, the threads sure look clean and uncorroded. WTF?

[comingbackdown]

Helpful tip for when you can't afford hot metal...

pour some water or non-flammable oil on it, go to town.

[padauk_dust]

Nice work. Sometimes the hardest part of a job is figuring out "petty" issues like this. I ran into quite a few nightmare bolts while taking apart the Miata.

There's always a way.

[theholycow]

Helpful tip for when you can't afford hot metal...

pour some water or non-flammable oil on it, go to town.

Interesting idea. I still couldn't take a torch to the fuel filter/line even if I tried to fill the filter with water, but I could have felt better about my dremel work.

What kind of non-flammable oil exists? No oils come to mind that don't burn easily.

[comingbackdown]

Helpful tip for when you can't afford hot metal...

pour some water or non-flammable oil on it, go to town.

Interesting idea. I still couldn't take a torch to the fuel filter/line even if I tried to fill the filter with water, but I could have felt better about my dremel work.

What kind of non-flammable oil exists? No oils come to mind that don't burn easily.

Mineral oil?

[theholycow]

Mineral oil?

http://en.wikipedia.org/wiki/Mineral_oi ... erformance
Mineral oil is the main fuel used by professional firespinners and firebreathers. It is chosen for its high flashpoint and low burning temperature. As a firebreathing fuel it is ideal because it will not tend to burn as a liquid, due to the high flashpoint, thus preventing blowback.
Well, I guess it's less flammable than some other oils...

[theholycow]

Update: Ran the fuel pump sans filter to empty the crap out of the tank but nothing came out. Removed the bed to get access to fuel pump hole, got fuel pump out, got the last 3 gallons out (I now have over 24 gallons of bad gas in containers), and got it almost all the way back together.

The retaining ring that holds the fuel pump to its hole is all rusty and was a bitch and a half to remove; it's totally refusing to go back in place. I'm going to see if I can get a new one.

[LHOswald]

i thought you already said you were going to replace the whole thing? if its giving you that much trouble, its most likely going to be better to replace the whole thing anyway considering its age and amount of rust

[theholycow]

The fuel pump retaining ring is totally separate from the fuel lines and filter, where were in a different place. I was expecting to replace the fuel line but I found out that it comes as an assembly that goes all the way from the tank to the engine and costs $250, so I'm going to re-use the old one.

I don't know if the retaining ring normally comes with the tank or the pump, but neither of those is getting replaced.

[theholycow]

It's alive!!!!!!

Took bed off, removed the fuel pump (big struggle with the retaining ring), emptied more gallons from the tank (total of over 24 gallons removed now from my 24 gallon tank), replaced fuel filter, struggled with retaining ring reinstalling fuel pump, bought new retaining ring for a whopping $26 (for a stamped out piece of steel!), failed to connect fuel pump ground strap, nearly committed suicide when I found out a fuel pump costs $300, moped around for a few hours, spent a half hour tracing wiring diagrams, went back out and re-tested fuel pump connector, reconnected ground strap, started truck.

[LHOswald]

that is the sex

[theholycow]

It sure is.

I drove it to the dump and finally got rid of my large collection of garbage that was building up. It drove great, just like it always did before.

Thank you all for your help and support.