Blazer rear Tank, filler and venting

[hotwls13]

I’m trying to finish up this tank relocation that was started by previous owner in my 70 gmc 1/2t lwb. I’ve got the bed crossmember notched out. Now I’m working on adding a fill, venting etc. I’m gonna put a metal box in the bed rear of the drivers side wheel hump. That will be the shortest route to the tank, should be downhill the whole way. I’m using a .50cal ammo can that I will trim up to fit, then mount it against the bed floor/inside bed wall. I’ll mount a marine stainless filler neck on top.

Couple of hiccups.

1. The 1 3/8” filler neck on the tank is an odd size for finding a hose. Plan to use small piece near tank, then have muffler shop do a custom bent pipe swaged (is that he term) to 1 1/2”. That way I can run a small piece of 1 1/2” hose between filler neck and pipe.

2. I’d like to vent the tank on both sides. I’ve heard if u don’t that are a pain to fill. My plan is to use some fuel hose up to a rollover valve. Mount it high (I think higher than the fill level is required?)

Any links to what you guys have used?? Trying to keep this inexpensive but functional.

Also, I’ve got short legs and short arms so putting the filler directly on bed floor is not an option. I also don’t want it in the wheel well

[71blksuper4x4]

You could weld in a blazer/truck fuel door.

[hotwls13]

Originally Posted by 71blksuper4x4

You could weld in a blazer/truck fuel door.

That would be the cleanest. But the only welder I have is a harbor freight cheapy flux. And my welding skills are minimal.

Plus I plan to replace this bed in the next year. It is is really rough. Just trying to get the truck functional and driving for now. I think I’ll do the blazer door (or some kind of door) on the next bed.

[jamie72]

if your going to replace bed soon, i`d just rig up a filler in the wheelwell behind tire.

[87Skier]

Originally Posted by hotwls13

I’m trying to finish up this tank relocation that was started by previous owner in my 70 gmc 1/2t lwb. I’ve got the bed crossmember notched out. Now I’m working on adding a fill, venting etc. I’m gonna put a metal box in the bed rear of the drivers side wheel hump. That will be the shortest route to the tank, should be downhill the whole way. I’m using a .50cal ammo can that I will trim up to fit, then mount it against the bed floor/inside bed wall. I’ll mount a marine stainless filler neck on top.

Couple of hiccups.

1. The 1 3/8” filler neck on the tank is an odd size for finding a hose. Plan to use small piece near tank, then have muffler shop do a custom bent pipe swaged (is that he term) to 1 1/2”. That way I can run a small piece of 1 1/2” hose between filler neck and pipe.

2. I’d like to vent the tank on both sides. I’ve heard if u don’t that are a pain to fill. My plan is to use some fuel hose up to a rollover valve. Mount it high (I think higher than the fill level is required?)

Any links to what you guys have used?? Trying to keep this inexpensive but functional.

Also, I’ve got short legs and short arms so putting the filler directly on bed floor is not an option. I also don’t want it in the wheel well

You could use the blazer equipment. The fuel venting is done by a "tube" that runs up near the fill tube. It has 3 lines, two from the tank on either side, and one to a charcoal vent canister.

Not sure how much work you want to do, but I've seen some guys making custom brackets to conceal the filler behind the tailights.

[jjzepplin]

I used a Blazer fill pipe like above And will eventually Weld in the original hole for the in cab tank. For now there is the old gas cap in the hole drilled through and plated on the inside to hold it in. Of course this means you have to drill a big hole in the side of your bed and in the floor of your bed but I had a Blazer to use for the template.

[hotwls13]

Originally Posted by jamie72

if your going to replace bed soon, i`d just rig up a filler in the wheelwell behind tire.

Where the tank fill is in relation to the bed crossmember, it makes more sense to me to go aft of the wheel well. Come up into the bed between the back two crossmembers.

Here is my box I plan to mount the filler in. It was a .50cal ammo box. I had to do a makeshift brake to make the bends.

Now just need to track down some hose and get some exhaust pipe bent and swaged (I think that's the term). Need 1 3/8" hose at the tank, and a piece of 1 1/2" hose at the filler neck.

[hotwls13]

Update: I'm close to putting the bed back on.

My filler doesn't have a vent. From what I have read, I should do TWO vent hoses? One on each side of tank? There are actually 3 lines coming off the tank, guess I will plug the extra on drivers side. I have a couple boat vents I picked up, but they aren't rollover valves. I'm guessing I need a couple rollover valves, then mount them up high in wheel wells (above where the filler top is?)?

[cebra]

I did the ammo can thing as well, I don't think it will look bad once the bed is coated.

[hotwls13]

Originally Posted by cebra

I did the ammo can thing as well, I don't think it will look bad once the bed is coated.

Looks like yours is a bit shorter. Hopefully mine isn't too tall and the gas station filler has enough room under bed rail. We shall see. I'm bolting mine on so if it is a problem, I'll yank it off and trim it down.

[Rufas]

I know the dilemma your going through. I used a gas filler door off of a late 90's Chevy truck and for the the bed mod to run the pipe through, I used a fuel pipe cover out of a late 80 Mazda pickup. No problems filling. The rear tank has just one vent located at the top of the tank. I vented it back to the filler tube and use a vented gas cap.

[hotwls13]

Originally Posted by Rufas

I know the dilemma your going through. I used a gas filler door off of a late 90's Chevy truck and for the the bed mod to run the pipe through, I used a fuel pipe cover out of a late 80 Mazda pickup. No problems filling. The rear tank has just one vent located at the top of the tank. I vented it back to the filler tube and use a vented gas cap.

That looks great and beautiful truck. I doubt I'm even keeping this bed (or this truck for that matter). Just want to get it back together and functional. Can't believe they don't have an actual "kit" for these tanks. They advertise the rear tanks as a "kit" but it's just a blazer tank with straps and sender. No real help in clearing the bed, venting, or getting fuel into the tank. I keep saying I should market a kit every time I'm cussing this tank. haha

[hotwls13]

Got the bed on last night. Then went to hookup the fuel filler line I had come up with. Just not gonna work. The 1 3/8" hose that connects from end of exhaust pipe to fuel filler on tank is crimping at the bottom. Needs another bend.

Do I search for some flexible 1 3/8" fuel hose?

Do I fabricate (or more accurately have fabricated) another additional piece of 1 1/2" pipe, bent at the end then have another 1 3/8" adapter welded on the end of that (then trim off the existing 1 3/8" end on existing pipe)? This would add a new metal pipe in the mix and require an additional hose union.

Do I scrap the existing pipe I have, have a new one fabricated with 2 bends and a new 1 3/8" adapter welded on the end? This would have to be dead on as far as length and bends etc.

Do i scrap this whole "mounting a fuel filler in a box idea" and find a simpler place to add a filler?

Just want to drive this thing and be able to add gas as needed.

Also, I was planning on putting the 1/2" vent line hose up in the fender (rear of fenderwell). How do i attach/secure the end of the vent hose?

Also, don't forget that this bed is trash so I will probably replace it once I have a driving truck to pickup another bed. So anything I do I would like to be able to move it over to the new bed.

[SeanB242]

I found this setup on line and I’m gonna try to pull it off. Not sure how easy it’s gonna be but well find Out. I don’t know who did it to give them credit

[hotwls13]

Originally Posted by SeanB242

I found this setup on line and I’m gonna try to pull it off. Not sure how easy it’s gonna be but well find Out. I don’t know who did it to give them credit

Yep, several ways to get there including the side marker light, the stake pocket and also cutting and welding in a later model fuel door.

All of those require more work/fabrication than I want to do (especially on this crap bed).

[hotwls13]

Finally think I have it!!

I had muffler shop cut and weld another 1 1/2” piece to another 1 1/2” to 1 3/8” adapter. I had them weld it at downward angle. This piece lined up right by the tank fuel filler. Then I use my previous bent pipe and connected that to this new one. I have 3 fuel hose junctions. One above bed at fuel filler, one connecting two metal pipes and another connecting to filler on tank. Hope that makes sense.

Anyway, it looks pretty good to me. Haha

I’ll post pics tomorrow. For some reason I can’t post pics from my phone because of some token issue.