Hi, I am trying to change the fuel filter on my car but the threads seem to be seized. The lines and filter are off a donor car and I don't think the filter has ever been changed in 175k. The threads are rusted and covered by rubberized undercoating.

I got wrenches on the line and filter but they didn't budge. I didn't want to keep trying in case the fuel line flare nut is seized to the line itself and have the end of the line twist off. Done that before.

Any suggestions?

 

line wrenches and PB blaster. the correct line wrench+ pb will get the job done. and good luck.

 

I would handle this in a couple of stages. First, spray the undercoated fittings with WD40 to loosen it up, use a wire brush to get the big chunks off, then spray again with same or penetrating oil of choice and leave it for a few days. Will come apart real nice.

 

both of those guys are right, a correct size line wrench and some PB blaster is the only way i will attack an old rusty fuel line

 

PB Blaster is some good shyt

 

This stuff works very well on fuel filter line connections, esp if the nut is frozen to the line. Follow the instructions as they say to blast it for 30 seconds or so.