replacing rubber fuel line on f-pump leak
 

My truck (72 350 engine 81 c10) was having trouble starting and I realized that there was a small leak and abrasion on rubber hose that joins between metal fuel line and mechanical fuel pump.

I replaced it and replaced the old hose that connected to inline fuel filter and carburetor to the metal line that threads into fuel pump.

The rubber hose is held in place by hose clamps. When starting truck it was leaking by the clamps connected to inline fuel filter and fuel pump.

I was wondering if there was any sealants that I could place on metal line that would allow rubber hose to slide on and seal while using hose clamps?

I know rubber hose isn't ideal but it is what it is. The rubber hose from fuel tank line to fuel pump is about 10 in. and the two rubber hoses connecting inline fuel filter between pump and carb are 6 in. total.

Re: replacing rubber fuel line on f-pump leak
 

I don't know of any sealer you could use for this. I know that it is what it is. I'm also not cutting on you for this. But the reason that the factory used steel lines between the fuel pump and the carb is the situation you find yourself in. Pressurized fuel may spray when you get a leak, or at least drip enough to get on many things including the exhaust manifolds. If you are using the whole setup from the 72, I would dig up a fuel line from a 68 to about 74 small block anything (presuming this is a 4 barrell Q-jet). If it is using the 81 style get something from about 78 to 86. If there aren't any good junkyards close, try craigslist for folks parting vehicles. Hope this helps.

Re: replacing rubber fuel line on f-pump leak
 

If you're going to use rubber and you want to seal it to metal lines, just flare the tubing slightly. Poke a phillips screwdriver in the end and crank it lightly around the inside of the tubing. That'll flare (or bell) the tubing enough to let you slide the hose on and get it to seal.

Re: replacing rubber fuel line on f-pump leak
 

There is no problem when sliding rubber tubing on metal fuel lines. I thought it may be problematic if I were to use sealant on metal lines when sliding tubing. Should I use different clamps for a more even seal.

Re: replacing rubber fuel line on f-pump leak
 

It should seal fine. You must be doing something wrong.

Re: replacing rubber fuel line on f-pump leak
 

The metal to rubber line just needs a light flare. Where the fuel pump out to metal line is at is a compression flare, just tighten. No plumbers tape is needed.

If it a manual fuel pump its only under light pressure---7 psi

Electric tank pumps should be all steel line to engine with flare fittings because of high pressure of ---40 psi +

All returns back to tank are not under pressure and just a light flare on the line is needed.

Re: replacing rubber fuel line on f-pump leak
 

It is a manual fuel pump with two ports.

The rubber hose that is leaking does not have a flare unlike the fuel pump port that receives fuel from tank.
I'll try it again tomorrow and use two clamps for each connection, might use fuel injections clamps since maybe I can tighten more without fearing that clamp will cut through hose. If that doesn't work I might use a sealant like hylomar on the metal to slide tubing over along with clamps.

Re: replacing rubber fuel line on f-pump leak
 

I wouldn't use sealer, light flair, you could double up clamps. If using worm or spring clamps, make sure the screws are offset 90-180*. (don't over tighten the clamps.)

Also make sure the steel line isn't split and your not trying to seal a 3/8" rubber line on a 5/16" steel nipple.

Other thing, you could re-do the steel line or if that isn't an option, you can get a brass, barbed nipple and use that off the pump.

Re: replacing rubber fuel line on f-pump leak
 

This is what I was wondering. Easy thing to overlook/assume....

Re: replacing rubber fuel line on f-pump leak
 

I used all Summit parts starting at the fuel pump with a 5/8 inverted flare to -6 an fitting then a 90 degree an to cloth braided hose up to a -6 an fuel filter then to carb with the proper fitting. No clamps and no problems. Seems like it was in the $40 range. I know its more than a cut fuel line with an inline fuel filter and clamps, but I feel safer. If I use an inline filter with rubber hose and clamps I try to install it before the fuel pump on the suction side without cutting metal lines. Hope this gives you a few ideas.

Re: replacing rubber fuel line on f-pump leak
 

While I doubled clamp the hoses and it stopped the leak. But, I had to use 4 inches of the old hose. So, as soon as rejuvenate from Thanksgiving, gotta replace it.

One other thing,my inline filter reads 3/8, but I am thinking that maybe 5/16 would fit on barb or possible switch to a 5/16 filter. The port on fuel pump looks like it is 5/16.

thanks for info.