Author Topic: New fuel tank installation questions  (Read 416 times)

Offline adgalloway

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New fuel tank installation questions
« on: March 05, 2019, 07:50:50 PM »
I'm putting a new fuel tank in a 1984 K10 short bed. It's a 16 gallon Spectra tank. I'll be using the old brackets which I've sanded and painted, with new straps, sending unit, filler hose, etc.

1. How do these straps attach to the brackets? I see three holes in the strap and what looks like 3 rivet heads in the factory brackets (see pictures)

2. What do folks put as a liner between the bracket and the tank?

3. Is there only one way to install the fuel sending unit into the tank?

4. Is it best to strap the tank into the brackets and then hoist it up into position as one piece?

Thanks

Offline 75gmck25

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Re: New fuel tank installation questions
« Reply #1 on: March 06, 2019, 06:21:24 AM »
1. How do these straps attach to the brackets? I see three holes in the strap and what looks like 3 rivet heads in the factory brackets (see pictures)
I've never unbolted mine from the brackets, so I don't have any advice.

2. What do folks put as a liner between the bracket and the tank?
I've seen liner material offered in catalogs, and it looks like big, wide strips of rubber.

3. Is there only one way to install the fuel sending unit into the tank?
If you have the right sending unit (left vs. right) I believe there is only one way to install it.  The fitting in the tank has a keyway that determines the alignment.  IIRC, the fuel fittings will point toward the bolt holes on the tank brackets.

4. Is it best to strap the tank into the brackets and then hoist it up into position as one piece?
I don't think there is any other way to easily mount it. 
- Bolt on the brackets and the filler tube so its a complete unit.  Plug the sending unit wire in, and make sure the ground wire is also sticking out from the sending unit. 
You also need to install the hoses on the sending unit.  About 12-16" of hose should be plenty.  I am now using SAE J30R9 fuel injection hose and fuel injection clamps, but as a minimum you should use SAE J30R7 carburetor hose, since it will hold up to Ethanol much better.
- Then put a board (1x8 works well) under the tank for support and use a floor jack to move it higher until it fits between the frame and the bed. 
- Make sure you guide the filler tube into position as you raise it. You will also have to guide the tank lines and wires into place as you jack it up. 
- Once in position, you can hand-thread the bolts through the frame into the bracket and tighten them in place with a ratchet.
- Connect up the fuel hoses and sending unit.  Sand the frame clean and use the ground wire to ground the tank.  There should be a bolt hole already in the frame.  You could also use one of the bolts for the tank bracket.

Bruce

Offline Irish_Alley

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Re: New fuel tank installation questions
« Reply #2 on: March 06, 2019, 07:44:42 AM »
I'm putting a new fuel tank in a 1984 K10 short bed. It's a 16 gallon Spectra tank. I'll be using the old brackets which I've sanded and painted, with new straps, sending unit, filler hose, etc.

1. How do these straps attach to the brackets? I see three holes in the strap and what looks like 3 rivet heads in the factory brackets (see pictures)
you could grind the old rivets off and use bolts
2. What do folks put as a liner between the bracket and the tank?
i used an old mud flap off a dump truck. think it was a little too thick but it worked
3. Is there only one way to install the fuel sending unit into the tank?
the lines should be facing inwards
4. Is it best to strap the tank into the brackets and then hoist it up into position as one piece?
its best to put the brackets into place without the tank and weld nuts to the brackets, then remove the brackets from the frame put them on the tank loosely and install back onto the frame loosely,i put one bolt into the one bracket and lifted the tank up and then attach the hoses and snug everything back up
Thanks
make sure you dont make the rubber hoses too long or theyll kink
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

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Online ehjorten

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Re: New fuel tank installation questions
« Reply #3 on: March 06, 2019, 09:02:24 AM »
1. How do these straps attach to the brackets? I see three holes in the strap and what looks like 3 rivet heads in the factory brackets (see pictures)

-In the newer trucks, they do indeed have the extra bracket welded onto the fuel tank bracket.  This has a stud in it for mounting the plastic fuel tank liner under the tank.  I don't see any easy way to replace these straps.  You could grind off the rivets and use bolts, but I think that is kind of cheesy.  What I did on my '77 was to grind off the rivets, then I found identical rivets and I used a hydraulic press to swage the new rivets, but the '77 doesn't have that extra bracket welded to the main fuel tank hanger.  On my '91 Crew Cab, I had the issue you did.  What I ended up doing there was just to buy new fuel tank hangers.  They come with new straps and everything!

2. What do folks put as a liner between the bracket and the tank?

-You can buy the strips from an aftermarket supplier; choose your favorite, or if you have a roll of roofing felt lying around, that is exactly what it is!  On my '77 I cut my own from roofing felt that I had, on my '91 I bought the material from an aftermarket supplier.  If I could go back, I would have just used the roofing felt because I felt that it was slightly thicker, more like OEM, and more durable than the stuff that I bought.  If you don't have any roofing felt laying around or don't have a buddy with some, I would just buy the kit.

3. Is there only one way to install the fuel sending unit into the tank?

-There is a LH and RH sending unit.  Put the LH in the LH tank and the RH in the RH tank.  There is only one way to install them.  fuel tubes should be facing inboard.

4. Is it best to strap the tank into the brackets and then hoist it up into position as one piece?

-You have to do this because if you don't, you can't get the fuel tank into position with the hangers already mounted.  Unless you have the bed and cab removed!  There are features on the tank that kind of show you where the straps need to go.  I install the brackets and straps and only lightly snug the straps.  That way you can move the brackets a little if you need to get them lined-up with the holes in the frame.  I use a floor jack with a large base attached to it...a piece of plywood or lumber or sheetmetal so that the tank will sit on it more stable.  Carefully raise it up and get one bolt in the rear bracket (upper, rear bolt).  Then you can gently lower the tank.  It will hinge from the back.  Watch clearances and binding.  You do this so that you have room to get in from the front of the tank and make the fuel connections, sending unit connection, and sending unit ground wire connection.  The hoses and wires are not long enough to do it any other way...unless you have the bed removed.  Then slowly jack the tank back into position, watching to be sure you don't kink the hoses.  If you are replacing the hoses, don't make them any longer than the factory.  There really isn't room in there for the hose to be longer, and they will likely kink.  One exception I found was on my '91.  I am running fuel injection rated hose and that stuff is not as flexible.  I had to make a little bit longer loops on the LH tank to keep the lines from kinking because the sender is so close to the lines on the frame that it is nearly impossible to get bulk hose to bend in the bell-curve shape the factory lines were in.

Hope this helps!
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline adgalloway

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Re: New fuel tank installation questions
« Reply #4 on: March 06, 2019, 09:18:56 AM »
Thank you to all three of you. This information had given me a lot to think about.  I'm hoping to tackle this project this weekend. I'm hoping to have this old truck on the road by the end of March.