Trying to change the fuel filter on my 1999 Bravada with 70k miles. It is the same configuration as the Bonny and I am following Dan'* writeup. Can't get the bolt on the fuel line to budge. Have been spraying with PB Blaster and using brand new Craftsman 16mm and 20mm open end wrenches. Starting to strip the 16mm bolt. Heading to Sears for a 16mm soft bolt wrench.

Any other suggestions? I imagine I can't torch it a bit because it is in fact a fuel line.

BTW- screw GM. No way they should of had used the materials for this connection. This is not a fluke problem- it is common and no excuse for a part that needs to be changed as part of normal maintenance. I will be putting some never seize on the threads if I get the old filter off.

Use a line wrench, that'* the one that looks like a box end wrench with a notch cut in it.

Thanks Dan, the soft bolt wrench equals the line wrench.

Getting maybe a little more mature with age. Years ago I may have twisted until something gave. In the case of the Bravada- if the line breaks where the fuel filter connection is- one has to drop the tank to fix. I am going to spray PB blaster on it daily for a week or two and then try the line wrench. I had a super solid connection on both the 20mm end and the 16mm end- yet I sensed it was going to twist and not free.

Wisg GM would have used a different metal to connect the fuel filter or used a never seize lube on the connection- this is a disaster waiting to happen...

Decided I couldn't wait- so started to work the frozen bolt on the fuel filter. It finally did loosen- using the line wrench. It never would turn without muscle until it was completely off the filter. When the filter was completely off- still could not hand turn the fuel line bolt.

Ran into another problem- could not get the filter off the strap. The bolt that holds the strap was also frozen an unaccessable. It also started to pour rain and I was outside. I decided to lube the outside of the old filter, and then turned the 20mm bolt for about 10 minutes and it finally came out.

Couldn't find my never seize, so I used wheel bearing grease on the threads of the new filter. Also greased up the outside of the filter so I could slip it easily on through the strap. Installed the new filter, started it up- checked for leaks- all is well.

I think I would have stripped or bent the fuel line and/or fuel line bolt if it were not for the16mm line wrench. Also- the fuel filter bolt/ nut is 20mm for those who don't want to use an adjustable wrench.

Finally- I have a new lube point for the Bravada and Bonny- the point where the fuel line goes into the flared threaded nut. I will be spraying that with teflon or something every few months. That being near seized really added an additional worry.

What I find works is to turn the filter instead of trying to turn the bolt on the line.