Truck Fuel and Brake Line Routing

[edwardb]

Getting ready to run fuel and brake lines and wondering what the rest of you are doing for the front to back runs. The manual shows running them in the bottom corner between the outer frame and floor. Then shows pictures from a 33 Hot Rod. OK, except that model doesn’t have the mounting brackets for the truck running board mounts intruding into that space. Which I'll be using for my build. I can still run the fuel and brake line in the corner. But I’ll have to loop around the mounts. For one spot specifically that would put the lines within 2-1/2 inches or so of the muffler. My sense is that’s probably not an issue. And could even use some insulation tape where it’s closest. But before I decide, just looking for some feedback and what others have done.

Further background: Since EFI (LS3) I'm installing a return style fuel system. I’m using an Aeromotive regulator. But instead of running both lines to the front with the regulator on the firewall, which is what I’ve done with my Coyote builds, I’m thinking of mounting the regulator in the back and have a very short return line to the tank. Not particularly handy. But what I’ve found with the Coyote builds is once it’s set I’ve never touched it. So a little extra effort reaching underneath for the setup is worth it to only run one line to the front. Plus saves some space on my already crowded firewall. I was originally going to use 3/8” hardline for my fuel lines, again like I’ve done in the past. But now thinking of using SS flex for the whole thing since it’s a pretty tortured route. Comments about any of that?

https://hosting.photobucket.com/images/ab234/edwardb123/IMG_2535.jpg?width=960&height=720&fit=bounds (https://app.photobucket.com/u/edwardb123/a/31737472-d15e-42e2-8d8e-965924ebbb8d/p/62301228-2058-4e0d-b182-b8a69d24ff44)

[Stillwater35]

I just did an EFI retrofit to my truck. I ran them through the area highlighted. I used hose for the whole thing and then also managed supply and return in this manner. Hope this helps a little.

Getting that close the muffler doesn’t feel like that big a deal. And I think you run then around those brackets. That’s what I did.


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[edwardb]

Thanks for the reply. Agreed that spot in the back is where they'd go through to the floor. The brackets (circled in the picture below) are what push the line(s) away from the corner and closer to the muffler and are the main reason for my question. Specifically the rear one. After thinking about it some more, I'm agreeing it's maybe not a problem. Also it would be pretty easy to make a heat shield over the lines in the area of the muffler.

https://hosting.photobucket.com/images/ab234/edwardb123/IMG_2535_marked.jpg?width=960&height=720&fit=bounds (https://app.photobucket.com/u/edwardb123/a/31737472-d15e-42e2-8d8e-965924ebbb8d/p/e9044772-6154-4208-8a7e-9bb4c3d856e2)

[Stillwater35]

I went around them in my truck. No issues on a 95 degree day.

[JohnK]

Just thinking out loud, but if proximity to heat is a concern with the fuel lines one possible solution is to locate the pressure regulator forward of the point that the fuel lines run close to the mufflers. The flow of fuel through the dual lines upstream of the regulator will be much greater than in the single line downstream of the regulator, so heat buildup in the fuel will be much less of an issue. I realize that means running dual lines further forward but it may be a worthwhile tradeoff.

[Pat Landymore]

There is another option…essentially how I built my truck.

Run a single exhaust out the passenger side, with a (boost, vacuum or electrically operated…) dump if you want all the power available from your particular combination.

Before you call me crazy, hold on a minute.

The supplied FFR exhaust really isn’t 2-1/2”…it’s more like 2-1/4”. If you take another moment to do the calculations, two
2-1/4” pipes are equal in flow to between a single 3” and a single 3-1/4” system. Then no loud valve or dump would be required. Considering the work some folks have gone to running different mufflers and exhaust right out the back, I don’t think fitting a 3” single is any bigger challenge.

The good news is that leaves the entire driver’s side available for simplified (and cooler operating) pluming plus the routing of all the back half wiring can be done without worrying if it will get cooked.

[edwardb]

Just thinking out loud, but if proximity to heat is a concern with the fuel lines one possible solution is to locate the pressure regulator forward of the point that the fuel lines run close to the mufflers. The flow of fuel through the dual lines upstream of the regulator will be much greater than in the single line downstream of the regulator, so heat buildup in the fuel will be much less of an issue. I realize that means running dual lines further forward but it may be a worthwhile tradeoff.

Thanks for the input. I don't have an easy way to prove it, but I'm not expecting my setup to add any significant heat to the fuel. I have a pretty mild pump (Walbro In-Tank 190 lph) on a Pro-M full 3/8" in and out hangar and will have 3/8" send and return lines. Should be reasonably matched to the engine but still not pushing too much fuel through too small of lines. Which is where heat is often generated. Still planning the plumbing, but pretty set on having the regulator in the back and only a single line to the front.


There is another option…essentially how I built my truck.

Run a single exhaust out the passenger side, with a (boost, vacuum or electrically operated…) dump if you want all the power available from your particular combination.

Before you call me crazy, hold on a minute.

The supplied FFR exhaust really isn’t 2-1/2”…it’s more like 2-1/4”. If you take another moment to do the calculations, two
2-1/4” pipes are equal in flow to between a single 3” and a single 3-1/4” system. Then no loud valve or dump would be required. Considering the work some folks have gone to running different mufflers and exhaust right out the back, I don’t think fitting a 3” single is any bigger challenge.

The good news is that leaves the entire driver’s side available for simplified (and cooler operating) pluming plus the routing of all the back half wiring can be done without worrying if it will get cooked.

Yeah, I'm way beyond changing out my exhaust. My "baby" 430 HP LS3 is not quite the same as your turbo charged big block. This build is for cruising and I'm not trying to squeeze huge power or performance out of it. If the stock exhaust is an issue, it's easy enough to change out in the future. All exposed on the bottom. Appreciate the feedback though.

[Shades]

Oh so that's what those things are for. (the part of the frame the running board mounts to). Those really got in my way of trying to run straight lines in my hot rod. I thought they were reinforcements for the frame. For brake lines I zigzagged towards the outside (still under the large frame tube under the doors).
150952
Haven't done the fuel lines yet, but planning to use flexible SS the whole way and also zigzag. I already ground some of the notch in that mount a bit to make a little more room.

[edwardb]

Oh so that's what those things are for. (the part of the frame the running board mounts to). Those really got in my way of trying to run straight lines in my hot rod. I thought they were reinforcements for the frame. For brake lines I zigzagged towards the outside (still under the large frame tube under the doors).
150952
Haven't done the fuel lines yet, but planning to use flexible SS the whole way and also zigzag. I already ground some of the notch in that mount a bit to make a little more room.

Thanks for your input. I had forgotten that the hot rod also has an option for running boards. So those brackets aren't unique to the truck. My mistake. Your routing makes sense. But since I am actually installing the running boards it fills up that area enough I wouldn't be comfortable routing the lines out and around like that. The supplied brackets have a lot of adjustment in them and until I actually fit the body and running boards, wouldn't know how much clearance there actually is.

[House Money]

I am also running an LS3, I used a Corvette style regulator/filter mounted near the tank, that way the return line is short and only one line needs to routed forward to the engine. It comes pre-set at 58 PSI, exactly what the LS wants. I used Russell push-lok hose and routed it behind those tabs and then clamped it to the frame rail on either side of the tabs.

As for the rear brake line, what about routing that inside the cab right along the corner of the upper sheet metal floor piece just under the door opening? It could exit through the rear bulk-head near the seat belt tab that protrudes through the floor. I think it is small enough to be completely hidden by the sound deadener and carpet. You would probably wand to plan it out so that there is no coupler in that area though.

Gary

[House Money]

I am also running an LS3, I used a Corvette style regulator/filter mounted near the tank, that way the return line is short and only one line needs to routed forward to the engine. It comes pre-set at 58 PSI, exactly what the LS wants. I used Russell push-lok hose and routed it behind those tabs and then clamped it to the frame rail on either side of the tabs.

As for the rear brake line, what about routing that inside the cab right along the corner of the upper sheet metal floor piece just under the door opening? It could exit through the rear bulk-head near the seat belt tab that protrudes through the floor. I think it is small enough to be completely hidden by the sound deadener and carpet. You would probably wand to plan it out so that there is no coupler in that area though.

Gary

[McGuyver]

I used the same regulator/filter as Gary with a short return line. Ran -6 Fragola PTFE lines and fittings. I did end up trimming the running board brackets a little though. For the brake lines, take a look at the photos I posted under one of my albums. https://thefactoryfiveforum.com/album.php?albumid=1794

[edwardb]

I decided how I'm going to address this. Kept it pretty simple and it's done. Updated my build thread, but here also to follow up on the thread. Appreciate the feedback, but seems not everyone is using the running board mounts which I need to account for in my build. I decided to go ahead and run in the area as far away as I could but without any special routing around the brackets, to the outside, whatever. Until I have the body on and running boards mounted (basically near the end of the build) I really have no idea where things will end up and interference just isn't an option. So I put the brake line farthest out in a straight line just short of where the running board brackets would be if at their maximum adjustment in. Then ran the fuel line right next to that wrapped with a 36” piece of Thermo-Tec 14005 Heat Protection Thermo-Sleeve. At the last minute, decided to use a piece of 3/8” rigid SS tubing in that section. It’s slightly lower profile and maybe even more heat tolerant than the SS flex I used everywhere else. Plus a perfect fit for the Thermo-Sleeve. I had it along with the compression fittings on hand from previous builds.

This is the brake line installed first:

https://thefactoryfiveforum.com/attachment.php?attachmentid=151468&d=1627779080

Then with the insulated fuel line:

https://thefactoryfiveforum.com/attachment.php?attachmentid=151476&d=1627779131

The angle of the picture makes it look closer than it is. Closest at one corner to the muffler is about 1-1/2 inches. It’s more than that everywhere else. I think it will be fine.