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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: MarkS on January 06, 2010, 08:51:06 pm

Title: Replacing fuel pump
Post by: MarkS on January 06, 2010, 08:51:06 pm
Anybody have any suggestions on removing the fuel output line from the pump? The pump was installed when the engine was out and the shop must have over tightened the nut. I'm using a line wrench but the it won't budge. I'd hate to have the cut the line and have another one bent. It's not stock and it would be tough to re-bend a line and have it fit.

Any help would be greatly appreciated!
Title: Re: Replacing fuel pump
Post by: VileZambonie on January 06, 2010, 08:53:35 pm
Definitely use flare nut wrenches. PB blaster is your friend. Tighten the fittings if you can first then try to loosen them. Holding the wrenches in a position that allows them to be close to each other allows you to just squeeze hard to crack em loose. So position the wrenches strategically.
Title: Re: Replacing fuel pump
Post by: MarkS on January 06, 2010, 09:01:33 pm
Thanks to the set I just bought from you, Vile, I have a flare nut wrench. I'm not sure what you mean by positoning the wrenches... It's just one nut. And excuse my ignorance but what's PB blaster?
Title: Re: Replacing fuel pump
Post by: Layne on January 06, 2010, 09:02:47 pm
It's like WD40
Title: Re: Replacing fuel pump
Post by: VileZambonie on January 06, 2010, 09:10:26 pm
like as if you were squeezing closed a pair of vice grips. The right wrench is higher than the left wrench but in close proximity to each other. Now SQUEEZE
Title: Re: Replacing fuel pump
Post by: MarkS on January 06, 2010, 09:14:30 pm
but it's only one nut... the one right into the output of the pump.
Title: Re: Replacing fuel pump
Post by: VileZambonie on January 06, 2010, 09:18:00 pm
Is this mechanical or electric?
Title: Re: Replacing fuel pump
Post by: MarkS on January 06, 2010, 09:19:49 pm
mechanical
Title: Re: Replacing fuel pump
Post by: VileZambonie on January 06, 2010, 09:21:33 pm
Just snug it up and push with your manliness
Title: Re: Replacing fuel pump
Post by: MarkS on January 06, 2010, 09:26:20 pm
I gave it all I had but it appears to be twisting on the nut... or starting to skin the nut.
Title: Re: Replacing fuel pump
Post by: VileZambonie on January 06, 2010, 09:44:55 pm
Try to to tighten it a little first then Hercalees!
Title: Re: Replacing fuel pump
Post by: MarkS on January 07, 2010, 08:02:12 am
I hear ya! I'm going to give it another try tonight. Thanks for the advice!
Title: Re: Replacing fuel pump
Post by: Stewart G Griffin on January 07, 2010, 12:44:23 pm
i was also going to suggest wacking the wrench with a hammer---this could help break it loose.

But if you are using a flare nut wrench and it's beginning the round off the nut, i'm not sure what to do next besides cutting the line, which means you'll have to get a new line i think they're like $20 pre made.
Title: Re: Replacing fuel pump
Post by: SLOW-N-LOW74 on January 07, 2010, 01:00:51 pm
have you tried a set of vise grips that always helps.  Just a thought
Title: Re: Replacing fuel pump
Post by: jaredts on January 07, 2010, 02:41:27 pm
Couldn't he just cut the flare nut off and re-flare the end of the line and add a new nut?  The line would only get shorter by 1/2" or so?  First post says its not stock, so I assume he means the fuel line is custom bent and a replacement would also have to be custom bent???
Title: Re: Replacing fuel pump
Post by: Irish_Alley on January 09, 2010, 01:57:16 am
from what i understand the nut goes in the fuel pump so cutting i don't think would help nor would heating up the nut lol  ::). like vile said put a little behind it and it should bear free just watch those knuckles
Title: Re: Replacing fuel pump
Post by: jaredts on January 10, 2010, 02:29:33 pm
from what i understand the nut goes in the fuel pump so cutting i don't think would help

He's replacing his fuel pump.  Throw the pump away with the nut still in it.  Repair the line with a flare tool and a new nut.  Of course this is last resort, but if the hex is already getting rounded it may still be a good idea to replace the nut.
Title: Re: Replacing fuel pump
Post by: Irish_Alley on January 10, 2010, 08:17:21 pm
Didn't see that lol
Title: Re: Replacing fuel pump
Post by: Cubman on January 16, 2010, 03:24:03 pm
I am replacing my mechanical fuel pump as well. I couldn't get this nut to break loose either, so I undid the alternator and took it out still attached to the fuel pump.  Someone cut thr to put an inline fuel filter on and put a kink in one of the bends, so I would like to replace it.  Can I use brake line to make my own or did Chevrolet use copper for a certain reason?
Title: Re: Replacing fuel pump
Post by: Donut on January 16, 2010, 03:56:34 pm
Mine are steel lines.  IIRC, I did use steel brake line from the pump to the carb.  (I put an inline filter there too, so my bends didn't have to be perfect)
Title: Re: Replacing fuel pump
Post by: MarkS on February 23, 2010, 06:23:12 pm
It's been a while since I've been on the site. I just wanted to let everone know how things came out.

Vile was right... tighten a bit then loosen. I was just worried about ruining the brass nut. And yes I was using a flare nut wrench. Even so, I've found from experience never hit with a hammer or use a cheater bar. This almost always kills the nut. I was very close to cutting the line off the pump and just replacing with a new one but since it was custom it wasn't going to be as simple as buying one off the shelf. I found that the probable reason for the over tight nut was the flare on the custom line wasn't as well fit as you would expect on a factory line. It wasn't easy to center up and once I did get it started I had to tighten to the extreme to get it to stop leaking (started by hand... not cross threaded). Hopefully this is the last pump as next time the brass nut will be toast.

Thanks to everyone for the advice!