Removing 4 Repair NL2 Aux Tank

[PbFut]

Took a few shots of the tank and how the factory set up the auxiliary tank. It is equipped with a fuel gauged sender. Fuel is diverted using a 3 port manual valve. The valve is stacked with a second valve so it will divert both supply and return. This eliminates the issue of the return fuel going into the main tank and over filling. I had a 71 Chevy C20 with aftermarket tanks and this was a problem until I realized you needed to run the main to empty then switch.
As for this OEM tank, here are a few more pics.
After opining up the port for the sender unit, it was clear the inside of the tank is in pretty bad shape. There was a lot of water in the tank from the failed filler hose in the truck bed. I cut two access holes and will try to descale as best I can manually before attempting a chemical etch and seal.
I took a few shots so anyone looking for documentation on how the factory did the option will have some info. I add a second post with a few more. These with the 3 photos I posted above might help someone down the road.

[PbFut]

4 more shots

[Rods]

Following along and wondering if you have a source for having a new tank made ?

If not could would it be possible for you to measure the tank and position/location of the mounting holes fuel inlet and sending unit hole so as to being able for someone to make a new tank as I’ve seen this done using aluminum.
(See Pictures)

I have someone who can make the tank but needing this info.

The picture’s are of this being done by another member who I reached out to but didn’t have the needed info on the one he had made.

If I could find a tank that would be even better but haven’t had much luck.

Here’s some pictures

[BASE]

I’ve been meaning to get all the dimensions measured on mine, just so I could make a new one if I ever needed to. Mine is not the same design as the one PbFut has, or the pics you have there. If by any chance you are wanting the design I have I could make a point to get it measured this weekend.

[PbFut]

Rods That tank is some very nice work that I am sure I would not be able to afford. It is the factory design. I see that there is a new pickup/Sender unit. Do you know the part number and source by chance. I must replace my assembly as well.
I'll get the measurements later today for you.

[BASE]

Those aluminum tanks sure do look nice. I wish my aluminum welding skills were a little better, I’d take a shot at making a pair. Is there a thread on those tanks here somewhere?

[best view]

I have a mint factory one but it’s in pa iam in nh but if you pm my friend Dwayne over in the blazer section I am sure he would help

[PbFut]

OK No comments from the peanut gallery. Jr high school drafting class was a T-square and compass 5 decades ago I gave up attempting to draw the top. My eraser was giving up. I used a photo so the angles are distorted. Everything on the tank is 90 degrees except the front face angels back. Most everything was even on the inch as would be expected for 1972.

[Rods]

Originally Posted by BASE

I’ve been meaning to get all the dimensions measured on mine, just so I could make a new one if I ever needed to. Mine is not the same design as the one PbFut has, or the pics you have there. If by any chance you are wanting the design I have I could make a point to get it measured this weekend.

The tank in this thread and the pic of the aluminum one is what I need measurements on.

Thanks though

[Rods]

Originally Posted by BASE

Those aluminum tanks sure do look nice. I wish my aluminum welding skills were a little better, I’d take a shot at making a pair. Is there a thread on those tanks here somewhere?

I got those pics from a member awhile ago.

If I remember I just searched NL2 auxiliary tank and went from there.

[Rods]

Originally Posted by PbFut

OK No comments from the peanut gallery. Jr high school drafting class was a T-square and compass 5 decades ago I gave up attempting to draw the top. My eraser was giving up. I used a photo so the angles are distorted. Everything on the tank is 90 degrees except the front face angels back. Most everything was even on the inch as would be expected for 1972.

Looks great, I appreciate your effort on getting this so fast.

I will go over your drawing and see if I need anything else.

Thanks again

[Rods]

Originally Posted by PbFut

Rods That tank is some very nice work that I am sure I would not be able to afford. It is the factory design. I see that there is a new pickup/Sender unit. Do you know the part number and source by chance. I must replace my assembly as well.
I'll get the measurements later today for you.

The sending unit was a NOS original that was found on the web a few years ago.

Everything was made to same as the original specs as possible

[Rods]

Originally Posted by best view

I have a mint factory one but it’s in pa iam in nh but if you pm my friend Dwayne over in the blazer section I am sure he would help

Ok I’ll reach out to him

[PbFut]

Circling back to this project...does someone have a picture of the factory dash switch. My system is clearly oem and backed up by the glove box sticker. The gauge switch appears to have been replaced with a Archer Radio Shack toggle early on as the dash paint is well worn from use. I thought the factory would have used one of the lower switch holes blanks in the instrument cluster.

[Getter-Done]

Originally Posted by PbFut

Circling back to this project...does someone have a picture of the factory dash switch. My system is clearly oem and backed up by the glove box sticker. The gauge switch appears to have been replaced with a Archer Radio Shack toggle early on as the dash paint is well worn from use. I thought the factory would have used one of the lower switch holes blanks in the instrument cluster.

I found this old thread.
Hope this helps.

Link: https://67-72chevytrucks.com/vboard/...el+tank+switch

[PbFut]

Yes I did see that but would like to see in place. My instrument panel does not have a hole for that factory switch but appears original. Correct color, that funky tope shade, and ware looks right. But the switch is on the left metal area of dash under what i think is the oem sticker. Oem tank harness is hacked. Was the switch in the metal area or in the instrument cluster. Was it under the light or wiper switch?

[Getter-Done]

I will post the link if you want.

[Getter-Done]

http://67-72chevytrucks.com/vboard/s...=1#post5746173

http://67-72chevytrucks.com/vboard/s...d.php?t=476843

http://67-72chevytrucks.com/vboard/s...d.php?t=572530

http://67-72chevytrucks.com/vboard/s...=560607&page=2

http://67-72chevytrucks.com/vboard/s...d.php?t=535733

These are all from this link that jocko shared this info

Link: https://67-72chevytrucks.com/vboard/...xtra+fuel+tank

[Mike Bradbury]

Mine did not have a switch on the dash but on the side of the drivers side rocker. Just a manual 3 position ball valve.

[best view]

The switch on the floor is to switch the tanks the switch on the dash is to switch the gas gauge

[Mike Bradbury]

Huh, I never used my tanks and when I bought the truck the saddle tanks were the very first item in the dump so I never used or needed that switch. I guess I never knew what it was for. Good to know after all these years.

[PbFut]

Thanks everyone for the replies but I still do not feel we have a complete answer to the question at hand. I started this thread to somewhat document the details of the 1 year only 1972 factory option NL2 Auxiliary Fuel Tank. Long story how I came to this point and maybe topic for another thread, but in any event, the question right now is on the factory switch used in the option. Getter-Done posted a photo in post #40 that I had seen a few weeks ago while searching and it confused me a bit as to where the factory location was for the switch. My truck has a toggle switch in the same location as Getter-Done. My truck also has the original factoy sticker on the dash. What was confusing to me was if the original switch was in the location of the toggle or if the factory had placed or intended to place the switch in the instrument cluster position 2 below the light switch. There appears to be room for the factory switch shown in post 40. I realize now that the ware marks on my dash is not from use but from the bezel used on the factory switch. So I assume that even though the factory could have used position two on the interment cluster it must have been mor efficient to simply drill a hole on the metal portion of the dash. What is also clear is that the original factory switch was probably not very robust as I have only seen toggle switches in use. The photos below I posted for documentation. With Instrument Panel removed you can see the available mount which was could have been used for manual chokes though I believe they were mounted below the wiper switch on opposite side of the steering column. The ware marks on both sides of the toggle switch are not from use but from the original factory bezel used on the factory switch. The marks line up perfectly to the bezel used on the instrument cluster for the factory wiper and light switches. I have a suspicion that it was intended the switch be in position 2 on the cluster and a labeled in the style of the lights and wipers be used. Likely the expense of changing the cluster was too great to justify, so they simply slid the install to the left and called it day. Pictures below show my truck with a previously swapped toggle switch, how a factory bezel covers ware marks indicating this was the factory location of original switch. And a couple shots of original switch plug hacked to use the replacement toggle.

[Old_Gold]

Here are a couple of pics from my 72 GMC. one shows the factory switch for the sending unit selector in the dash, the other is the fuel line valve on the floor, hope that helps!

Jim

[PbFut]

Thank you for the pics. I was thinking I could use a simple rotory switch and wiper knob on the dash and it would duplicate the look and function without having to source an original switch. The plastic valve label was available a few years ago but I've not been able to source one so far. My truck is far from show but a reasonably clean driver. Sure would like to find one of those plastic valve labels.

[67RS/SSx2]

PbFut, have you found the information you were looking for? I do not have source for a replacement switch or dash label, but I do have the NL2 option on my '72 C20. Mine has the original-style rotary switch to switch the gauge between tanks. A previous owner added an electric valve to switch between tank fuel/return lines.

I found a manual switch at a marine supply that switches the return lines as well as the fuel lines. Not certain it will physically fit in place but at ~$180 I am not sure I want to go that route.

My tank is out awaiting a decision to try to have it cleaned and sealed, or have a replacement fabricated.

Thanks for the thread and I will be glad to help if I can.

Dee