Hope you're able to use this cuz I just pulled my sending unit out for ya. (It was still accessible during my rebuild). From the interface of the lip of the sending unit connection and the polyethylene tank straight to the bottom is 11.25 inches.

 

Thank you. I am a little confused about your reference. If I drill a hole in the flat part of the top of the tank, it would be 11.25 to the bottom of the tank?

I am happy it is that deep as I think the reed switch senders have more increments the longer they are. The really short senders do not have enough space for that many switches.

I appreciate your effort.

 

Let us know how this goes. I was thinking about something like this the other day, but I wasn't sure what was out there. I just replaced the sending unit in mine, but I apparently got it in a little sideways and the float arm is hitting the side before it can go past half full. That was stupid of me. Going to have to drop the tank again.

 

Have you tried MTS fuel tanks . They make fuel cells for the military and they have quality products to include fuel cell senders.

 

I actually started another thread asking about the best brand of senders a few days ago but got no replies. Whatever sender I would go with if it goes in the stock location, I would have to modify it to hold my in tank pump. I got to thinking that a vertical type sender may be a better solution. I have used some MTS parts over the years and some of their stuff is good. In the other thread, I was asking if there was a difference in CJ replacement senders or if they were all the same and just rebranded.

 

I just purchased an mts sending unit and pump for my yj. Works awesome and company salesperson on phone was very helpful. Website says it has tank, assemblies, and all the accessories for your cj. I highly recommend mts.

 

I like the first video but that's just the geek in me..

 

The geek in you should:smile2: also like the second video at 2:15.

Why have 1 when you can have 5.

 

FWIW - the bottom of the OEM 20 gal tanks was not flat except for about an 8"x8" section in the very middle. If you measure straight down from the sending unit hole, you won't reach the bottom of the tank (the sending unit is well off-center).

When I installed an aftermarket (floatless) sending unit in mine, I drilled a hole in the top of the tank as close to the center as I could (the retaining strap is pretty much in the center so I made the hole just to the left of the strap). Don't remember the depth there but I have it in my notes if you need it.

 

Any help, pictures notes you have would be great.

How did your floatless sender install turn out? More accurate?

Did you use a similar unit to what I am referencing?

How did you attach your sender? I would thinking two aluminum rings to sandwich the tank between and then I would have threaded aluminum holes to mount the sender. I have to pass the EVAP test with every SMOG check every two years here in California.

I was thinking of drilling the hole in line with the passengers side vent hole but more toward the middle.

You can see a picture of a CJ 20 gallon poly tank here:

http://www.mtscompany.com/images/miscjeep/cj_20gal_oem.jpg

Thanks

 

I used a sending unit from Summit that uses the same Ohm range as the factory gauge. It is pretty accurate, but it was too short for the tank, so I had to fab about a 1.75" extension for the tube to reach close enough to the bottom of the tank. I used the hole for OEM sending unit to mount an in tank fuel pump which also worked out pretty well.

The bottom of the tank measured about 13.25" down from the hole I drilled. The flange ring that goes in the tank had to be cut in two pieces to get it in the hole. Used a gasoline safe sealant to on the seal and the threads to keep it from leaking.

 

Nice work! Almost exactly as I imagined it could be done.

(1) Did you make or buy the flange ring?

(2) How were you able to extend the sender?

It looks like you had the hole marked a little farther up and closer to the center strap.
(3) Did you discover something that caused you to move where you cut the hole?

(4) How did you connect the fittings to your fuel pickup (old sender).

Everything looks great. Thanks for all the information.

 

Nice work! Almost exactly as I imagined it could be done.

(1) Did you make or buy the flange ring? It came with the sending unit, but it's a fairly standard bolt pattern that can be purchased or fabricated.

(2) How were you able to extend the sender? I disassembled the sender and cut the original tube. I had a piece of scrap aluminum tube that fit over the original like a telescope.

It looks like you had the hole marked a little farther up and closer to the center strap.
(3) Did you discover something that caused you to move where you cut the hole? Yes, I drew some marks on the top of tank to estimate placement for the hole. I then drilled a small pilot hole and used that to adjust position more precisely... my estimate was a little off and I decided to move the sender a little farther from the retaining strap to make sure there was a flat surface for the flange to seal inside the tank.

(4) How did you connect the fittings to your fuel pickup (old sender). I cut off the factory nipples off the pump and used some AN-6 compression fittings to connect to the PTFE stainless-braided hose.

Everything looks great. Thanks for all the information.

Hope that helps.

 

BUMP...hoping Spieg8 will answer the questions above before I start collecting parts...

And a couple of more questions...

"FWIW - the bottom of the OEM 20 gal tanks was not flat except for about an 8"x8" section in the very middle."

(5) I see you marked on the tank a square. Is that the 8"x 8" section that is flat and the deepest?

(6) Does the internal pump you have reach into this deepest section of the tank? I would not want to maximize the sender depth only to have it go deeper into the tank than the fuel pump can pick up fuel.

I see that VDO makes a reed type sender that is a depth of 350MM

VDO Gauges 226-635 = 13.7795 inches

VDO also makes a unit that is 330MM

VDO Gauges 226-633 = 12.9921 inches

The way I am thinking of mounting the sender is to have a 1/4" aluminum ring on the inside of the tank and a 1/4" aluminum ring on the top of the tank sandwiching the tank material between the rings. This will raise the sender up 1/4" plus 2 cork gaskets but it will remove glue from the installation.

Thanks so much.

 

BUMP...hoping Spieg8 will answer the questions above before I start collecting parts...

And a couple of more questions...

"FWIW - the bottom of the OEM 20 gal tanks was not flat except for about an 8"x8" section in the very middle."

(5) I see you marked on the tank a square. Is that the 8"x 8" section that is flat and the deepest? Yes, that was my best estimate.

(6) Does the internal pump you have reach into this deepest section of the tank? I would not want to maximize the sender depth only to have it go deeper into the tank than the fuel pump can pick up fuel. Yes, I used a pump/bracket for a Ford Mustang that has a dog-leg in the bracket that offsets the pump toward the center of the tank. I was able to modify/extend the bracket so it picks-up from the very bottom of the tank.

I see that VDO makes a reed type sender that is a depth of 350MM

VDO Gauges 226-635 = 13.7795 inches

VDO also makes a unit that is 330MM

VDO Gauges 226-633 = 12.9921 inches

The way I am thinking of mounting the sender is to have a 1/4" aluminum ring on the inside of the tank and a 1/4" aluminum ring on the top of the tank sandwiching the tank material between the rings. This will raise the sender up 1/4" plus 2 cork gaskets but it will remove glue from the installation.

Thanks so much.

One other thing to keep in mind is that there is not a lot of space between the top of the tank and the underside of the tub. You don't want to make anything stick up too far on top of the tank or it may rub on the bottom of the tub.

 

I can see the limited height from the drivers side wheel well (thanks for the heads up). I think the VDO sender has less sticking up on top of the tank than the sender you chose. The metal ring on top of the tank will make the install and future replacement (if necessary) easy. I think I will be ok with the extra 1/4" plus the gaskets.

 

did you ever get an answer to this question, i want to do the same thing on my cj7 with factory 20 gal tank. i replaced the sending unit and it failed in 2 years just outside the warranty, i also need tank depth

 

Here is what I figured out with the part numbers:

https://www.jeepforum.com/forum/f8/please-show-me-your-tank-fuel-pump-setup-4308482/