Replacing fuel lines....

[94 at Large]

Advice from any that have done this would be greatly appreciated. Do I go with factory style hard lines that can be ordered in sets for front and back or create my own from diesel rated fuel hose? How much of a pain is this to do? I'm thinking of tilting the bed rather than removing it and not dropping the tank to get to the lines. Also, while I'm at it, am going to delete the tank sock, add an in-line fuel filter and probably get rid of the lift pump and go with a Walbro, which most of this can be had from leroydiesel. I welcome the challenge but I know my limitations and with shop rates being what they are I would like to save a few bucks. From what I have been able to gather it appears to be pretty straight forward but figured I'd put the question out there for those who've been there, done that.

 

[SnowDrift]

Good question. I'm faced with this on my "old" '95, too. I'll keep tabs on this post.

 

[Paveltolz]

My two cents. With the Bed off, raised tilted sufficiently (you be the judge) it shouldn't be too hard to do. It wasn't that bad dropping the tank either but I'd done it a few times (another story).
The adapters sold by Leroy will thread on to the fuel lines at the tank as well as the ends near at the LP.
Diesel rated fuel lines can be secured at the OEM supports along the frame rail and routed up the fire wall to the FFM. Just be sure to secure them so they don't flop over on to the exhaust manifolds or cross over. Might as well do the fuel Return lines while you're at it.
Replacing the OEM lines will make installing the Walbro or other aftermarket LP with an auxiliary filter that much easier as you'll not need to figure out how to fit all the lines and looping or fabricating hard lines to make the routing work with the new set up. OEM LP is about 8" long and is straight through flow. Walbro and Filter set up...not so much.

My Air Dog uses 1/2" lines so there's a splice from 3/8 to 1/2 on both sides of the thing (should have asked Leroy to source 1/2" adaptors...oh well). That and its own peculiar routing makes for a poor photo subject for your walbro to reference.

 

[jrsavoie]

I used OEM lines and left the tank sock in place.

Unless you already have, On a 94 I would make up a dual lift pump relay upgrade or buy Leroy's. As long as you are putting an order in you just as well Get the ready made kit.

 

[Missy Good Wench]

I would run steel where I could.

If you can get the truck up enough to work under it easily, you can remove the old factory lines and use them as patterns for your new lines.

Even the diesel rated hose is far more vulnerable under the rig.

Good luck

Missy

 

[Will L.]

As long as your replacing it, I would bump it up to 1/2" tubing. Use carbon steel, stainless steel, or aluminum for any tubing of solid line and sae 30r9 for the "rubber" line keeping everything rated for the newer fuels. You might not be using much of that fuel now, but in 7-8 years that's about all that will be available anywhere in the US. I would run as much solid tubing as practical, because it is near permanent, where as the rubber will have to be replaced again down the road sooner. My preference is aluminum, it is so easy to work with. Keep in mind isolating the different metals is best to stop corrosion from electrolysis, a little piece if rubber goes a long way. I have kids that are always needing bicycle tubes replaced, so guess what I use.

The factory does what is cost effective for assembly and gets it to the end of the warranty period. It does not mean it's the best option. Bigger line is more costly by a buck or so, multiply that by the thousands, that's why GM uses the smallest possible.

All fuel pumps are a volumetric pump that gets a longer life by pushing more product at lower pressures with less drag and static lift. Pressure is a result of restriction, which you will get by itself at the ip. For the rest of the system let it flow as easily as possible for best results. Think ftb mod- no one ever decreases fuel line size on purpose in any fuel system. The simple rule of thumb is what size is you pump inlet, that is the minimum size line to use. Your new pump will have 1/2", so...

If you are into it that far I would do the whole system and be done with it. Yes, return lines as mentioned above also, if one line is toasty why would the smaller thinner one next to it be spared? I prefer lifting the bed as to dropping the tank, but what-evers clever, The rest of the work will be under the truck. While you loose the sock, maybe put in the "magical" rod from Leroy to eliminate the sure to go bad sending gauge and increase the pickup to into the tank to 1/2" at the same time.

While I'm adding to your list of work, do you have a fuel pressure gauge before the ip? Instant diagnosis of future problems and extended life of the ip to know when the lp has died.