air in fue lines

[Exekiel69]

We spend this sunday at Charlies (landscapeman) working on one of the toys, we have replaced the rear tank on the truck (1993 f350) soon we found out the fuel lines connected to the tank where leaking so we decided to cuyt them off and put fuel hose on its place (3/8 multifuel hose) and when we tried to bleed the air out well we just cant keep it running with the rear tank. At first we thought we connect the fuel lines the wrong way but even though we switch them we still can't keep it running from the rear tank we have to switch to the front fast before it goes off, no fuel coming out most of the time just what ever fuel is left and just air. We tried several times with both hoses and no fuel so far, so is there any other way to tell wich hose is the right one (one is biger than the other I know, on the fuel sender), also is there any other way to bleed it other than using the shrader valve at the fuel filter?

Thank you.

 

[towcat]

ez-
unless you have problems with your sender/feul pickup assy, the whole thing will bleed out itself when you run it for a while(5-10mins). yes, the larger one of the two is the feul feed and the smaller is the feul return.

 

[Exekiel69]

I have the holley red on mine so I don't come to this problems but we start it on the front tank and switch to the rear to bleed it but it never gets to the point where it runs stable. I figured it was the larger hose but since I use the 3/8 hose for both steel fuel lines I though maybe I miss it and connect the wrong one but still can't get the air out. We also thought maybe there was more than the shrader valve to bleed it but that is all I used to bleed mine before. I guess will have to check the fuel pick-up but I doubt that would get broken it look in good shape when I installed it.

 

[93turbo_animal]

I had to replace about 3 feet of line on mine on the rear tank and when I got it together I started on the front tank then went out and found me a long stretch of road and flipped it to the rear then I just held on for the ride till it stopped surging

 

[Exekiel69]

I had to replace about 3 feet of line on mine on the rear tank and when I got it together I started on the front tank then went out and found me a long stretch of road and flipped it to the rear then I just held on for the ride till it stopped surging

You see Aric, Charlie did hold it and yes You are right it does keep on, in this case for longer but this one still had to switch back to the front before it went off. I guess I'll have to check both hoses again and heep bleeding.

 

[93turbo_animal]

sounds like you still got an air leak some where EZ I'm sure you'll find it

 

[LandscapeMan]

Exekiel,
Thank you for all the help you have been to me on many projects.
Thanks to all for there reply's. We are a bit stumped on this one.
Hmnn, the idea of finding a long road and holding it to the floor sounds interesting.

If it is self bleeding maybe we can just try to keep it running with out actively trying to bleed it. As we have not had much luck bleeding it.

Perhaps we might try running down the road and switching the tanks till it bleeds itself out?

Thanks again for all the help!!

Charlie

 

[tractorman86]

Exekiel,
Thank you for all the help you have been to me on many projects.
Thanks to all for there reply's. We are a bit stumped on this one.
Hmnn, the idea of finding a long road and holding it to the floor sounds interesting.

If it is self bleeding maybe we can just try to keep it running with out actively trying to bleed it. As we have not had much luck bleeding it.

Perhaps we might try running down the road and switching the tanks till it bleeds itself out?

Thanks again for all the help!!

Charlie

if that dosent work then take the line off the lift pump and put a little air pressure to it that is a surefire way to find leaks but dont use a ton of pressure tho u might make more leaks

 

[Exekiel69]

Exekiel,
Thank you for all the help you have been to me on many projects.
Thanks to all for there reply's. We are a bit stumped on this one.
Hmnn, the idea of finding a long road and holding it to the floor sounds interesting.

If it is self bleeding maybe we can just try to keep it running with out actively trying to bleed it. As we have not had much luck bleeding it.

Perhaps we might try running down the road and switching the tanks till it bleeds itself out?

Thanks again for all the help!!

Charlie

Well there is lots of long roads around there and you are right the bleeding have not succeed so (miles per gallon are down to the floor ) we might as well run it on I70 maybe? That sounds like a good idea since yesterday Charlie would have it half throttle and it would keep running.

 

[DeepRoots]

why not just take the fuel line off near the fuel filter, take a handheld vacuum pump and a small bottle (like for brake bleeding) and pull the fuel up to the filter? Fill the filter and get on with it.

drew

 

[LandscapeMan]

This may be dumn questions, please bear with me.
Do the fancy factory fuel line connectors have anything to do with the system being self bleeding? Exekiel said they appeared to have orings inside, I was wondering if they allowed trapped air to escape. I know, crazy idea but can't figure out what is going on so I am grasping at straws.

After initially hooking up the lines with the factory connectors which appeared to be in good shape. The truck started and ran fine with no bleeding at all. But we later discovered it was leaking like crazy from the top of the tank area where the connectors are located. We dropped the tank and replaced the factory lines and connectors and line with 3/8" fuel line and hose clamps. I don't think we have any air getting in there.

Any ideas on how the system self bleeds and if using the factory connectors has any effect?

Keep those ideas comming. We spent all afternoon trying to bleed this truck.
So I think there may still a problem somewhere in the system. But I would be willing to try just holding down the pedal and seeing what happens. Also how can we confirm that we don't have the lines hooked up backwards? Could we have hooked them up backwards the first time with the factory lines and that be the cause of the initial fuel leak? Just thinking out loud here searching for possibilites.....................

Thanks,
Charlie

 

[LandscapeMan]

why not just take the fuel line off near the fuel filter, take a handheld vacuum pump and a small bottle (like for brake bleeding) and pull the fuel up to the filter? Fill the filter and get on with it.

drew

I was posting at the same time as you. Great idea!! I do have the handheld vacumn pump and we will give that a try.
Thanks!!
Charlie

 

[Exekiel69]

Yep I like that one too. Funny is that we used the same pump to empty the tank yesterday and I did not come with that idea having it right there. Also it will prove if we connected it right.

 

[DeepRoots]

yup, thats how I move really thick oils and the like. Much easier to pump air out, than to pump oils in, if you know what I mean.

 

[93turbo_animal]

hey Charlie the way the air is purged while running is either the air goes into the cylinders causing your surging or it is passed to the return line and sent back to the tank where it is let out the factory fittings have nothing to do with the ability to purge air but if not sealed it could cause a major air in fuel problem