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Morning all,
I've been having a real annoying time with slow leaking fuel pumps. Yes, more than 1. So I am convinced its something I am doing wrong.
Reference the picture, the slow leak is occurring in the area with the red circle. In the first pump, I thought maybe it was too loose so I tried to tighten it in place - ripped a hole in the bottom of the bloody thing...
Ok, new pump, new strategy. I clamped the new one in a vice and tightened the fitting as far as it would go and still keep the 90 degree angle for the fuel line.
Checked the car yesterday - STILL a slow leak. At this point, I am thinking there HAS to be a gasket for this thing that doesn't come with the part...Any ideas?
jim-81 is right. Make sure the teflon tape is safe for gasoline. Only apply the tape in the direction that will not unravel as you tighten the fitting and stay 1/8" back from the end of the fitting. Otherwise the tape could break off, plugging up your fuel filter.
Hi 78,
There wasn't any sort of gasket originally.
I've found with both fuel lines and brake lines the hard line and fitting must align perfectly with the opening the fitting is being tightened into.
You CAN'T use the fitting to pull the hard line into position as it tightens.
There should be VERY little resistance as you turn the fitting. It should tighten most of the way with just your fingers.
Have you checked that?
Regards,
Alan
correct
flare must line up with the seat in the pump.
bend tube until it allows flare nut to thread by hand.
use flare wrench and hold square part of pump with
open end.
teflon will allow the fitting to turn free and reduce bind of nut
allowing a better tightening.
Allen's advice is spot on. The sealing area is between the face of the flare and the machined mating surface of the fitting. Check the flare to ensure it is a double flare and for damage, especially if you are reusing an old fuel line. If it is dinged, cracked or out of round it will leak. The flare and machined seat of the fitting should mirror one another. You should not need teflon tape. Since it is leaking is at the seat so the fuel is either passing by the threads of the nut or between the tube and the nut. Using teflon tape to stop the leak is a band-aid. The tape is now holding the fuel pressure not the metal to metal seal of the tube to the fitting. Given the pressure, vibration and heat the pump is subjected to it will most likely leak at some point, usually when it is the most inconvenient.
You can also run into a problem if your pump to carburetor fuel line has been replaced with a stainless line at some time. Due to the hardness of stainless it is sometimes very tough to get a good seal.
Pull the fuel line off. Clean up the flared end really good, and clean the mating surface inside the fuel pump. Inspect the flared tube end for any damage (nick, burr, crack, etc.). If there is a nick of any kind, you can polish the flare out with a little 220-grit sandpaper on your fingertip. Also, inspect the pump to make sure there is not a crack or defect in the pump outlet fitting/block.
Before you re-install the line, but a small dab of assembly lube (like LubriPlate) or wheel bearing grease on the back side of the flare where the nut rides up against it. Also, put a dab of lube on the threads of the nut. This will allow you to get proper torque without having to tighten so much. Tighten the fuel pump end of the line into the pump with your fingers, wiggling the line a little as the nut seats to assure proper mating of the flare to the pump cone. Then snug it up using a backup wrench on the pump outlet.
Be prepared to sleep in the spare bedroom tonight, because you're going to smell like gas, and your wife will kick you out of bed.
Fuel pump slow leak
