Saddle tanks, anyone ever....

[CG]

get rid of your behind the seat tank and just use saddle tanks? I have two large saddle tanks on my 67 I was thinking about using on my 71 K20 someday.

I was thinking about taking the tank out of the cab and putting one out back, but my spare is down there and I like it like that.

So are saddle tanks a good option? Personally I cant see any reason why not, but maybe Im missing something real obvious.

[Ilike 72"s]

I did that on my 4x4. I took the aluminum doors off mine and threw away. One trip to the wrecking yard and purchased the flush hinged doors, filler neck,cap and hoses off a newer pickup and adapted to the top of my tanks. Then welded the doors in place. Works a lot better than the way they came. DENNIS

[CG]

Hey thanks for the quick answer. These tanks have the filler in the wheel opening so I wouldnt have to worry about any side doors.

[chevy29267truck]

ok the true saddle tanks are round and where mostley on one ton trucks and where also on some 3/4 ton trucks i am looking for the set of the round tanks you can put a gas tank inside the frame like ever one dose and the tanks are from a blazer,camper,jimmy,suburban or even a beer keg

[nicolas72gmc]

I've got some on my 1/2 ton, the po installed them for road trips with his overcab camper. I asked this question earlier and Andy said the only thing to think about is the fuel return line. I had the very same idea. Tired of smelling gas fumes.

[nicolas72gmc]

Originally Posted by CG

Hey thanks for the quick answer. These tanks have the filler in the wheel opening so I wouldnt have to worry about any side doors.

CG, yours sound like the same tanks I have.

[chevy29267truck]

hey guys i would like too see some pictures of the gas tanks too see if there the ones i think im looking for i do have the switch handle that gos on the drivers side on the floor when you open the door

[nicolas72gmc]

I do too. it is right to the side of the seat on the floor. Sorry I dont think I have pics though. let me look.

Nick

[chevy29267truck]

ok nick

[nightmare]

i have the saddle type tanks, but they are rectangular, outside the frame rails, and in front of the rear wheels (i'll have to get pics). anyhow, the problem that i am facing is that they don't have sending units, just a drain type plug at the bottom on the front. i don't really know of a way to get it to where a sending unit will work in them, if i even need one. my main concern is that there isn't a way to tell how much gas is in those tanks. i think that if i have a sending unit mounting flange welded to it, that should work. and since i have two of them, just get a dual tank switch that allows for a connection to the gas gauge, instead of having the 3-way switch that only directs the fuel. any thoughts?

[mrein3]

When I got my truck it had one leaky saddle tank with no gauge. The PO said don't worry about the leak, use it first. When the truck starts bucking you know exactly how much is in there - none.

What I did is drop the tank and had the leak fixed by a radiator shop. While I had the tank on the bench I installed a fuel level sender assembly that I purchased from JC Whitney that included a gauge. The gauge I mounted knee-knocker style next to a trans temp gauge I added.

I'm thinking you could toss the seat tank. Purchase TWO sender gauges from JC Whitney or similar. Then rig the sending wires up so they display on one of the gauges via a switch. Put that gauge in place of the useless battery gauge on the stock bezel. Then toss the no longer needed large fuel gauge and replace it with a large tach.

[nightmare]

i didn't think of that mrein3. i'll look into it.

did the original saddle tanks come with sending units, and worked with the existing gas gauge?

[tkeduk8r]

Im thinking about adding a tank back into my 72 C20 that the PO took out of the truck due to rust issues at some point. I was actuallyt thinking of making a cardboard pattern and fabbing my own tank to best utilize the space tween the frame rail and the bedside. Then I was planning on finding a 90 Ohm sending unit the fit the best or modding as needed and using the factory fuel selector switch to the left of my gauges and complete it that way. My issue is finding a new bedside (deer took out my existing one) that has the factory fuel filler in it.
--Mike

[nightmare]

interesting tkeduk8r. mine has the filler neck in front of the rear tire (doesn't go through the bedside).

so the existing fuel gauge uses a 90 ohm sending unit?

[badpeanut]

I'm putting an old aftermarket saddle tank on the drivers side of my pickup which will fill through the wheel well. It didn't have a return line, but it was dry from sitting so I drilled a hole and welded one in. It doesn't have a sending unit so I didn't have to worry about switching that. I found an electric switching unit that switches supply and return lines for two tanks so I won't have to worry about overfilling either tank. I mounted the switching unit to the inside of the frame rail where the rubber lines between the in cab tank hard lines and trucks hard lines are. I then mounted a toggle switch under the dash. All I have left to complete is to clean the inside of the saddle tank and mount it.

[djw32]

Badpeanut,
We will need some pics.

[Ilike 72"s]

Here's pictures of my gas door. DENNIS

[badpeanut]

Originally Posted by djw32

Badpeanut,
We will need some pics.

Here is the only picture I have on my computer--the saddle tank test fit in place.

If you are looking for information on the switching unit I can get that?

[djw32]

I like the ideas in this thread. How many gallons can the stock saddle tanks hold?

[nightmare]

Originally Posted by djw32

I like the ideas in this thread. How many gallons can the stock saddle tanks hold?

With the tanks like Badpeanut posted, I calculated them to be about 20 gallons (IIRC)

I'll recalculate it once I get home.

[nightmare]

Ok, so the outside dimensions are: 15 5/8" x 10 1/4" x 27" = 4324.21875 in³.

This equates to 18.7195 gal, but since this is the outside dimensions, its probably more like 18.5 gallons.

The only question that I really have about them is do they spill when you make a turn, like the in-cab tank does?

[mrein3]

Originally Posted by nightmare

i didn't think of that mrein3. i'll look into it.

did the original saddle tanks come with sending units, and worked with the existing gas gauge?

nightmare, sorry I didn't see your question earlier. The saddle tank in my truck was one of the popular dealer add ons from that era. It had NO sender. While I had my tank on the bench I drilled a hole in the top and added a sender that came in a sender/gauge kit I purchased from JC Whitney. Actually I set the empty tank on the ground, filled it with water, then drilled a hole in the top with a hole saw in my drill. I'm not afraid to say I'm a chicken when it comes to drilling steel with steel over a tank full of potential gas fumes. I figured drilling into water wouldn't kill me where drilling into a tank of potental gas fumes could.

Regarding the amout of fuel they hold...
It has been a month or two since I filled up (salt season around here) but I know for a fact I've never put in more than 18 gallons in the saddle tank. I'm thinking it is around 17-17.5 gallons when I run it dry then fill it again. My saddle tank doesn't leak but then neither does my seat tank. If your seat tank leaks, you need a new gas cap. Even now that gas is down to $1.599, if you're spilling it that is money down the drain.

FYI...
These tanks are made of plate steel. The radiator shop that cleaned mine out and sealed it said that fact saved that tank. Most 35-40 year old stamped steel tanks can't be repaired and need to be replaced when they develop a leak.

[tekno62]

Nice work - do you have photos of you doing the work

Originally Posted by Ilike 72"s

Here's pictures of my gas door. DENNIS

[joemacho]

my brother s 69 long bed has these saddle tanks and his has sending units in them works with original gas gauge ill get some pics some time tommorro and he has an extra set.

[Longhorn Man]

Originally Posted by tekno62

Nice work - do you have photos of you doing the work

you don't want to see photos of him doin the work... he's real ugly.