Author Topic: Fuel pump leak  (Read 1641 times)

Offline adgalloway

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Fuel pump leak
« on: April 28, 2019, 07:43:12 PM »
I've got a 84 K10, there is a brass flare fitting that threads into the fuel pump, and had a nipple on the other side for a rubber hose. Same setup at the carb, with a new rubber line connecting the two.

Fuel is seeping steadily at the pump where the brass flare threads in, I've tightened it as far as it will go, but still leaks. Also tried another fuel pump with no change.

Any suggestions? I thought about RTV on the threads?

Offline Irish_Alley

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Re: Fuel pump leak
« Reply #1 on: April 28, 2019, 10:53:43 PM »
http://forum.73-87chevytrucks.com/smforum/index.php?topic=37329.msg313262;topicseen#new
think he was going through the same issue. dont be cheap, inspect the fitting and replace or fix the issue. fuel will cost you your truck in no time
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Online bd

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Re: Fuel pump leak
« Reply #2 on: April 28, 2019, 11:25:41 PM »
Did you use an inverted flare fitting with a 45° seat?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline adgalloway

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Re: Fuel pump leak
« Reply #3 on: April 29, 2019, 07:33:53 AM »
BD, I'm not sure, I used what the fellow at the auto parts store pulled off the shelf for me. I wouldn't be surprised to learn he gave me the wrong fitting. You said inverted flare with 45 seat, do you know what the threads are? I may try to get a replacement today. Appreciate your help.

Irish Alley, thanks for the link I'll read through. I may wind up ordering a metal line with flare fittings already installed. I'm not trying to be cheap, just looking for advice. Appreciate your help.

Online bd

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Re: Fuel pump leak
« Reply #4 on: April 29, 2019, 08:20:53 AM »
5/8"-18 TPI
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline MIKE S

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Re: Fuel pump leak
« Reply #5 on: April 29, 2019, 09:50:22 AM »
Thread sealant will do no good on an inverted flare type line. The threads have nothing to do with sealing this type of connection. Its all  got to do with the flare. Use a backup wrench to hold the block on the fuel pump and a tubing wrench on the line or fitting. If you get a preformed line stay away from stainless steel. It is very hard to get to seal due to the fact that the metal is hard. Use regular steel for the line.

Offline BillWill

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Re: Fuel pump leak
« Reply #6 on: April 29, 2019, 12:09:17 PM »
That link Irish_Alley listed was from a post where I was having the same issue and I was simply not taking the entire fuel line out of the truck to work on and didn't see the nick in the threads, as well as it helping me to truly clean/prep the threads properly.  Once I was finally able to see everything and start over.. problem solved.

Take everything apart and take pictures.. without doing those things so I was able to post in forums I would have been fighting it a long time.  Post some pictures of what you are running into as I"m sure it will help those with more knowledge give you direction.
1986 chevy K10 Scottsdale
305 w/700r w/np208 w/AC
3.73 gears 10 bolt rear
3" lift on 33's